I have had the Kitchen Aid KEMS308S for 5 years. I had not noticed that the microwave power was low. I doubt that power will be an issue. I assume that many ovens have cool down features. They are not running when the door is open. It is ture that the fan makes some noise, but it isn't that noticable. When I originally purchased this oven I had been intending to get individual ovens, but it turned out that the individual ovens had been discontinued. I see no difference between your choices because they are all double ovens and when one fails, they both fail wheras individual ovens could be replaced individually. I have not heard of the microwave section showing a high rate of failure. You didn't even mention the advantage of the micro/convection. It is not just a microwave, but a real convection oven with a broiling (sort of) element. It is not a speed oven because it does not microwave and heat at the same time. Actually it CAN microwave and crisp via the broil element. Anyway it is a small second oven that can bake a pie or bread (or a small trey of cookies I suppose). It heats far faster than the regular large convection oven because it is small. I find it very useful. The only problem is it is occasionally in use when I would want to reheat a cup of coffee etc. I keep an old microwave in the garage for those cases. While I hope I have relieved your concerns, I believe that there IS an issue. I have had no problem with my oven, and it has been several years since the Main contingent of problems: similar models have encountered a higher than normal thermal fuse blowing during the large oven self cleaning cycle. Unfortunately, the fuse is located on the back of the oven and is a $50 item and shuts everything down. Of course, most people see no problem (myself included) and the problem is certainly due to excessive heat behind the cabinet that could probably relieved by making sure that there is a little more open space back there since you are still installing cabinets? In any case, this is probably a general issue. Other ovens have failed on self clean cycles. At this point, many people concider the self clean to be a marketing ploy and don't use it. Perhaps we just don't make enough spattering roasts, but I have easily wiped down the main oven. It wasn't stuck on hard. Perhaps the surface has anti stick coating? My self cleans have been done mainly to test the thermal fuse problem. By the way, the microwave interior is stainless steel and IS much harder to clean. In fact, that last sentence is probably my most important piece of information. I imagine it would apply to other convection microwaves.

It's pulling hot food out of the microwave on top that will be unsafe, unless you & your family are really tall. You should be apprehensive; it's not a good idea. Microwave ovens should be positioned near the R/F, since that's the source of most food that goes into a MW. Positioning either a countertop or built-in MW on or under the countertop is far preferable for safety & ease of use, especially since you use a MW a lot. Another option is to get a range, which will provide you with one oven, and stack the MW over a single electric convection oven. Our 36" DCS range oven is huge & can handle full size baking sheets. If you have kids, they can learn at an early age to safely use the MW & start being independent, but only if they can reach it without climbing on something. Otherwise you will be doing what they could be doing far longer than any of you will like.

We're getting the Wolf Combi Steam + Wall Oven. Haven't used them yet (a broken granite slab is pushing the install dates back), but our plan is that we'll probably use the steam oven most of the time, and the big oven just for holidays, or when we need a second oven or the broiler. Again, not speaking from experience just yet, but my understanding is that we'll probably use the steam oven for a lot of things that we currently do in the microwave (like reheating leftovers). My wife has never been a big microwave fan anyway, so we'll probably just continue with our small countertop model. I would personally rather leave out the drawer microwave and invest that money in a full-size traditional oven. I don't think Wolf ever said that their steam oven has broiler like capabilities. They do say that they can somehow brown the outside of meat with a combination of heat and steam. As long as you'll have at least one oven with a broiler though, I don't see that the lack of a broiler on the Wolf should sway your purchase decision. Finally, keep in mind that the Wolf 30" steam oven is really a 24" oven with a bigger faceplate that matches their traditional ovens. It only goes up to 450 degrees as well, so I'm not sure that your pizza stone will do you much good.

So, make a niche(s) with the proper electric service and size to have a built-in put in if you really need it to sell (but I bet you won't)--if you're planning to sell within three years, get the built-ins already, but otherwise, they're going to be just so many used appliances. If yours are truly ratty, you can buy new versions of each. If you WANT a speed oven, and intend to use it as such, that's another story. Go for it! Read through the manuals, etc. But I think you'll find that it's not at all the same thing as your Breville toaster oven. You can use the convection oven settings on a speed oven to perform some of the same functions, but it's a real oven, with limitations, not a toaster that tap dances. I sometimes use my speed oven the way others use a toaster oven--mainly for heating up frozen appetizers or reheating casseroles when other ovens are full, but my old (dead) toaster oven was beloved for making great toast, which a speed oven isn't, and not for other uses. I do zap sandwiches on MW mode, and once in awhile lightly defrost or melt, but if I used a microwave more, I wouldn't have such an expensive machine doing it. I agree with putting enough thought into a remodel that it won't limit resale, because you never know what the future will bring--thus make sure there's place for built-ins to be built into--but unless it's a flip, it should be designed for your own use and enjoyment, and you used the key words "heavily use" and "love".