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.

HU, I don’t know if what I have to say will help. I discovered that oven makers are making 24” ovens in Stainless Steel. I have ordered two 24” Frigidaire ovens that are nearly the same size as the old Thermador. The appliance dealer’s installer came and said he would figure out how to make a divider, and a mason contractor I had for another job said he could resize the brick wall, but I guess it’s up to the appliance installer to put in the divider board. So check with your appliance dealer to see if his installer can figure out how to support the upper oven.

I grew up in a kitchen with two totally different wall ovens. One had a great broiler and rotisserie, and opened to the side. The other was fantastic for baking, especially things that needed a consistent and gentle environment. It was also good for gigantabirds. Both could handle most ordinary tasks. For instance, cookie baking marathons, or multiple chickens. Both were at optimal height. The side opening one could take advantage of what would have otherwise been a dump area by a doorway. The drop down door was by a wall where the other couldn't have fit. The design of my non-attached ovens (Gaggenau combi-steam and single) are so heavily weighted to stacking that they would have looked dumb if they hadn't been. Giving up separate optimal height ovens for that is one of the decisions I question constantly. It solved some other problems, but I still rue it. If you have the money and space for two single ovens, do it! And remember, if they're independent ovens they also don't have to be next to each other if the design works better to separate them.

I posted this in the appliance forum, but I am copying here in case someone else asks: Miele, Bosch and GE Café/Monogram/Profile make a version of what you are looking for. There are some differences but they all will accomplish 95% of what you are looking for it to do...and the 5% you can probably live without! http://mieleusa.com/Product/Details/1198 That is the miele speed oven. The higher end models have full broilers and can be ordered with a trim kit to match their ovens. Their menu is the most robust with a ton of options for all of their modes, plus some step up features like a probe for cooking. You also have options on there ovens depending how much you want to spend. The combo can range from about $8k to $10k depending on the pairing. http://www.bosch-home.com/us/products/cooking-baking/wall-ovens/combination-ovens/HBL8751UC.html?source=search This is the bosch one. It has a simpler control, less deluxe feature wise but still has a broiler and solid microwave. It does less in the "speedcook" department, but if you just bake/broil or microwave its a good option. This is also easier for install, its 2 units, but they install in 1 single opening to 1 single power supply. So if one breaks you can replace it and the other will work. This should be around $4k http://products.geappliances.com/appliance/gea-specs/CT9800SHSS The GE one comes a few ways. The Café is a one piece unit, with one power supply. The drawback to that is that if the control panel fails...both units will probably not operate since its a shared control. Otherwise they do some different things. They use convection and a halogen light heating element. So it doesn't have a traditional broiler, but the halogen works well for that. There is a lot more emphasis on speed cooking, as the menu is programmed with hundreds of different items that you can speed cook. Its an established design though they GE has been selling for years. The Café will be $3-4k and the monogram will be separate components so figure more like $5-6K