Higher power hobs are usually larger diameter hobs, and are designed with the expectation that cookware with larger diameter magnetically susceptible surfaces will be used with them. You may not get all that power when a pan that is too small is used on a large diameter hob (assuming that the hob will operate with the pan). That is, interception of the magnetic fields among the hob poles by the pan base may be incomplete. Very roughly, it is the available watts per square inch that is common to the hobs. In any case, the high power mode is useful for quickly getting a large thermal mass (e.g., pot of water) up to temperature, but is overkill for most cooking (simulated wok cooking or meat searing might be an exception). Once boil is achieved, the power level has to be significantly reduced (immediately) or there will be boil-over. It the pan or pot is covered, then the heat loss will be further reduced and the hob power will need to be reduced yet further to avoid boil-over. Usefully, the range of power settings for induction hobs is quite large, even without considering boost mode. The high end usually beats any pro-like gas burner, and the low end gets lower than most gas burners can regulate to (not sure about versus old-time pilot lights though). kas

I think the question is about ranges rather than cooktops. As the posts demonstrate, there is more flexibility with separate ovens and cooktops. It is possible to fit a cooktop over an oven in a lower cabinet, but there can be space constraints because the cooktops are often wider than their their nominal width might indicate. Very few 30-inch wide induction cooktops will actually fit into a 30-inch wide North American base cabinet. There is a discussion of this on "The Induction Site" which is linked below. The cost of going with a separate induction cooktop and electric oven can be a budget buster, and may involve additional costs. For example, it might or might not require some rewiring because of the need for having two separate 240v feeds (one for the cooktop, another for the oven.) Some houses are already set up for this but others may not be. Sometimes it is easy to do, sometimes not. In my old house, I would need have to have a subpanel installed or possibly may have to relocate and replace my house's existing panel with a larger one, assuming I figure out how to shoehorn the assembly in without a complete cabinet overhaul. So, I have been pondering induction range choices, too. I can say that hob layout does matter, but one size does not fit all. You have to think about how YOU cook, how YOUR kitchen functions, and what YOUR personal preferences are. Having the big burners in the back allows for having a touchpad on the control top at the front of the stove. Maytag/Whirlpool ranges do this. Some people like having the big pots in the back for reasons such as keep them away from small children. My own preference is to have the biggest burners in front, but I also want the flexibility of being able to run multiple large pots. The downside to this set-up, is that the controls go on the backsplash. Right now, I've only found three induction stoves which have controls on a front panel, the slide-ins by GE ($2500-$2700) and Electrolux ($3200-$3400) and Viking's induction range ($6700 and up depending on color options). These costs are above the stove budgets for some folks (me being one in that economic boat.) SO, in looking at the less expensive induction ranges, I ran into another set of issues about how well the hobs accommodate pans that are off center. I started a thread with some questions I had, but I'll summarize the point here as an example of how layout and design figure into the choices. This question came up when I was looked at the the new Samsung NE597N0PBSR 30" freestanding induction range. It has two 9-inch square burners on the left side and, on the right, an 11 inch diameter circular burner in front and a 6-inch diameter burner in the back. I took some pans along to get a sense of cooktop layout for the range. What I found was that my 12 qt. stockpot on the back burner gets pushed off center by the backsplash. The front side of the pot overhangs an inch or so over the boundary ring of the front burner. The stockpot's magnetic base --- which is what the induction burners "see" ---- is fine. It completely covers the back 6" burner and does not intrude over the front burner. The problem is that the pan flares wider and the sides overhang the front burner space. When I put one of my large frying pans (around 12 inches in diameter at the top), the stockpot pushes the frypan forward two inches and some. As far as I could tell, the frying pan's 8 1/2 inch base was still within the front burner boundary, but it is off center. I do this kind of thing all the time with my existing gas stove, but I do not how well it will work or not work with induction. The Samsung user manual indicates that it "may" not work with induction. I do not know one way or the other, at this point. So, more to think about. Here is a link that might be useful: The Induction Site

I have a new 30" Frigidaire induction range that replaces a 2011 model which died. Induction on the old one worked very well. The new one has problems. I am pretty sure the issue is with the induction coils Frigidaire is putting in the new models. Try putting a large pan with an inch or so of water on the large hob, put it on power boost, and watch how it comes to a boil. If it's like my new range you will see only the center boiling. This appears to be because Frigidaire is putting 5 1/2 inch induction coils beneath all four hobs. If you can find the Frigidaire partslist on line it shows that there should be 5 1/2 inch coils and 8 1/4 inch coils. For whatever reason, to me it looks like they are only installing the smaller ones. Makes it really bad for cooking on the largest hob, and even not ideal on the two medium ones if you watch them close. I cannot brown meat on the large hob- it browns the center but not the edges unless I shift the pan around to apply heat to different areas in turn. Or trying to gently simmer a large pot- it simmers the center but leaves the sides cold. Frigidaire sent a repair man out from A&E. He had no experience with these ranges, but agreed it looks like a design or construction flaw, but since it 'works' he could do nothing.

@Sukhman Waraich Yes! honestly i was so glad that i found this thread. I had let something boil too long & the same silvery marks occurred, they looked oily almost and i could have sworn they were under the glass. i spent about 5 minutes scrubbing with a magic eraser and wiping with a cloth and they disappeared. I wish id taken pictures to show you. if youre unsure about a magic eraser, try it on a window first to see that it really is non scratch.