The 15K will be MUCH better for stir frying, searing, etc. There are some on this forum who will claim you can't cook properly without a 22K burner :-)

Magically I sear and Wok just fine with 15k BTU burners.

Personally I would opt to get a set up with 4 burners that are ALL 15,000 BTU.
There is no need for 6k, 9K and little simmer burners if you have double stack 15K burners which are also very low simmer burners.

"Need" seems a strong word in this context. If I were spending a bunch of money on a new range (as I did early this year), I'd be hesitant to get something that didn't have at least 15k BTU on at least one burner. In fact, I'd prefer more than 15, and bought and paid for more. The thing is, as already pointed out, if one is combining gas and induction, and one or more induction burners fits the fast or high or fast/high heat model, you might not "need" this from the gas burners too. Your call about what you want to do with what.

I'm not so sure about minimum output for this or that technique (even if we wave our hands about measurement differences). One can, indeed, sear a steak properly with a 15k BTU gas burner (and a good pan, properly pre-heated, and a good steak) and one can, equally, bring a large pot of water to a rolling boil. I prefer the flexibility of higher-output open burners for such tasks, and a few more, but 15k will work, no doubt about it, if you know what you are doing and are accustomed to the tools you have. One can get a nice sear on a steak (beef or tuna) on a lower output burner, but I had to take more care when my max was 13k, and was never entirely happy with the time it took pasta to return to a boil once it was added to the pot. For true wok cooking . . . well, it's not my forte but high heat seems key and the experts seem to think that more is better -- and dedicated pro wok burners seem to be very, very hot indeed.

One may think they are woking just fine with sealed 15k btu burners when in fact they are not.

There are average Cubans and North Koreans that think they are living just fine under Communist dictatorships. But if they experienced life in the West or Japan they would probably change their minds.

No pan,not even cast iron, will retain all the heat put into it.

Pre-heating ad infinitum is not a substitute for good power.

You only need 300 degrees surface temperature to sear. Deeageaux gets a little worked up about searing, but it's really not that hard. You do need your pan to be hot enough that it will remain above 300 degrees when the cool meat is put into it, but that's all.

The Wolf 15" induction does give you 3kW on boost, which is a lot of power, but usually boost is only available for about 10 minutes, at which point it reverts to 1.8kW. It doesn't say that this is true of the Wolf, but it's something you might want to inquire about. Either way, it's hard to get that power from a flat induction unit into a round bottomed wok. That puts you either in a flat outside/round inside cast iron wok, which has a fairly small footprint, so takes a lot of time to heat up the sides, or a flat bottomed wok, that's more like a high sided frying pan. There's also the Demeyere clad stainless wok with ball feet and a round wok shape. I've never used it, nor found a thorough review of it, so don't know how well it works.

If woks and sears on meat meant to be served blue aren't your thing, I'd be more concerned about the physical sizes of the elements.

I have the 15" Wolf gas, and use it mostly for fairly small things, and once in awhile a large kettle. I sear on my induction, as I do most of my cooking, because it's faster, cooler, easier to clean up. I only use the gas for things that do better on gas period and when I need more burners. I can fit a large stockpot, 11" in diameter on the back burner, but it overlaps the front one a little bit, leaving room for only a small pot. My induction (24" Gaggenau) has an 11" element, allowing me to use my wider braiser and big dutch oven without any problems. The 8+" larger element on the Wolf induction has adequate power, but no great size. You're not supposed to use a pan that's bigger, though with most induction you can go an inch over the ring. That crowds the other element, however. Also, note that the smaller element doesn't boost. Just for information's sake, too, all of those "Wolf exclusive" features mean that they have their own electronics, exclusively, as do most makers, not that the same features, like pot sensing, and melt setting, don't exist on other induction.

Do you need a 15K BTU burner? Not if you cook moderate amounts in moderate sized pots and don't have any specialty needs, like top tier wokking. Home cooks have been cooking up masses of fantastic foods on home ranges that topped out at the old standard of 9.6K BTU. People have their old O'Keefe and Merritt and Chambers ranges restored, and buy restored ones new to them, because the old ranges were great. I used to entertain (small groups) using just two gas rings and some ingenuity. No one needs 15K BTU. The more powerful your burners the quicker your pot will boil. My old kitchen's gas cooktop took at least 20 minutes to boil two quarts of room temperature (to start) water at sea level. I hated it. That was a bad cooktop (definitely underpowered, certainly not up to "normal" specs). The little Wolf is a very nice little cooktop. I like it a lot! It dances circles around the old one. Water boils pretty fast (though not as fast as 3kW induction), simmers are all they say they are, etc.

I use my 12" De Buyer mineral steel pans for Searing steaks on my 15K BTU burners and I guarantee they SEAR just fine.
These pans get virtually red hot in no time and sear incredibly well.

As for Wok I use my 14" carbon steel hand pounded wok on a Wok ring, heat it up, second the oil hits it it is literally boiling and starting to smoke, just how hot does one need?

I personally wouldn't want it any hotter I lose hair off my forearms as it is.

I am perfectly happy in every respect with 4 15k btu burners, they everything I need and then some.

Here is a link that might be useful: Debuyer Mineral Steel pan

Re: de Buyer:

I think something was lost in translation. Normally, the term organic would be reserved for carbon based compounds. To call a 99% iron pan "organic" is a stretch. Maybe in France carbon inclusions in iron makes the resulting mixture organic, in which case normal cast iron would be even more organic.

kas

Basically what they are talking about is that the pans are 99% iron and nothing else, meaning they are basically "Carbon Steel" No coatings of any kind like non stick PTFE.
Cast Iron I believe is a bit less pure being made of Pig Iron which is about 4% carbon and 3% silicon.
In order to be Carbon steel it has to have less than 2% carbon. They are less than 1% carbon.

I like them because for what ever reason they heat up REAL quick and super hot, moreso than my Cast Iron skillets do.
They are thinner than my cast iron, the pan is 3mm thick.

They are super non stick especially after a few months of seasoning the pans get jet black.
They are very smooth polished carbon steel, unlike cast iron which is very pebbly finish.

To me they are the best pans I own, same attributes as the cast iron but lighter and get super hot very fast and stay hot as long as you keep the flame up.

Kas, I think you're right about the use of "organic" in the De Buyer pans. I have some which were labelled "carbon steel" (Wikipedia definition "steel where the main interstitial alloying constituent is carbon").

I've always thought that the use of "organic" to describe agriculture was amusing, since all produce is organic. I believe the word was used as a contrast to ammonia based fertilizers, though now it means something broader and defined by law. In French, they say "biologique" to mean the same thing.

"Organic" can also mean free flowing, curvy, or happening as it may, as in nature, when applied to arts or activities.

I like my De Buyer carbon steel crepe pans too; maybe not quite as passionately as Nunyabiz, but they're really really good. :)

I would guess that the wok that Cooktek supplies with their induction wok is also carbon steel. However, it is more organic now than when it was new due to the load of oil baked onto the surface.

kas

Lets put it this way - we used to have a Viking cooktop with the 16k burner. Wife loves to wok & she hated the 16k sealer burner. Side got hot & bottom didn't. Now she has a 23k open burner and loves woking again. I do not know if it's the extra power or the fact that the heat goes to the center of the wok instead of the sides. But here's a hint - professional chefs find all the BTUs they can and send them to the center of the wok. Do you need a 15k burner - yeah for melting butter.

"Lets put it this way - we used to have a Viking cooktop with the 16k burner. Wife loves to wok & she hated the 16k sealer burner. Side got hot & bottom didn't. Now she has a 23k open burner and loves woking again. I do not know if it's the extra power or the fact that the heat goes to the center of the wok instead of the sides. But here's a hint - professional chefs find all the BTUs they can and send them to the center of the wok. Do you need a 15k burner - yeah for melting butter."
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Pure nonsense, I just use a Wok ring and all the heat is concentrated on the bottom.
I don't own a restaurant so really have no actual "need" for anything over about 15kBTU.
The reason they have them is saving SECONDS that add up to minutes over the course of a days cooking.

I am not in some timed event when I cook dinner.

15k Burners work just fine, more than plenty of power for the non commercial cook.

I'll back Nunyabiz on this one. Complaints about Vikings here are legion for a multitude of reasons, so who knows, perhaps ratfling's cooktop problem was that it was Viking. Don't know.
I have a 15Kbtu Wolf cooktop (not even the rangetop which is an open burner) and I can saute, sear and "wok" cook just fine. My problem is that I burn my dishes if I turn away for a few seconds - so it doesn't seem to be lack of power.

Aside from the time, the difference is the volume of food you want to be able to provide high heat to. I have a small household and my dishes and meals are scaled accordingly. If you have a larger needs, my experience may not scale.

Regardless, with the 3kw induction unit, I suspect you'll have all the power you need. Certainly, given inductions dramatic increased power transfer efficiency over gas, it will be within at least nodding distance of the power that deeageux or ratfing's more 20-odd KBTU units are able to impart to the food. (Back atcha diego & co. ;-) )