We installed a Miele Speedoven in 2012 and have no regrets. It is in a wall cabinet at counter height and is used all the time. It heats up very fast for baking allowing us not to use our 36" oven when not needed. It microwaves, bakes, and broils with all types of combinations of those heating choices. The drawbacks are the price and you need a 220v line to power it. The quality is excellent and have not seen another oven that can do what this does.

I have the Monogram Advantium. It's a multi-purpose oven. It can act as a convection oven - basically just a second oven and it can also broil. I use this for anything small where there's no point in heating up the big oven. Mine can hold a 9x13 pan of lasagna. It's also a regular microwave oven. The speedcook part combines microwave, convection and high powered halogen lights top and bottom. There's an onboard computer that decides how much of each to use for a particular food. The convection and halogen brown, broil or roast while the microwave speeds up the cooking process. We use the speed cook part all the time and we absolutely love it. Browned crispy fish sticks and fries in 4 minutes, crescent rolls in 2-3, etc. It does the best baked potatoes ever. The oven also can act as a moist or dry warming oven which I've used several times but the problem is that when it's warming it can't be doing another cooking job. So I'm getting a new Kitchen Aid warming drawer with my remodel that also does slow cooking like a crock pot. It has a few other features like proof that I use when setting dough to rise and melt or soften for butter. All in all, it's like a swiss army knife. It's the most expensive thing in our kitchen and was worth all the money I saved up to buy it. We absolutely love it. We're glad we got the 220v version too. My mom has the 110 and there isn't enough power. I tried out the different models available at a local appliance store. The Electrolux was nice but the controls were confusing. The Advantium controls were the easiest to use of all the ones I tried with the most features.

I just got the wolf speed oven and so far so good. I just did a partial kitchen remodel and got the 36 inch all gas wolf so wanted a smaller electric oven for a 2nd oven or for smaller meals. I also was happy to ditch my countertop microwave. I had space in my cabinets to put the 24" oven in without a lot of carpentry needed. The24" seems to be the same interior size as the 30" model, only the outer casing is different. At first I was a bit thrown off by the fact that the microwave turntable turns even when using convection mode but I've found that with the low riser its great for cakes and pies. They rotate as they cook very evenly. I haven't tried any of the microbake or microroast settings yet and the "gourmet" modes seem sort of silly, mostly just plain microwave.

If you type “Combi Steam Speed no other oven” in the search box in Discussions/Appliances you will get many threads on this topic. The down side I would see is not all of your larger pans such as half sheet/cookie/large roasters/pizza stones/etc may fit in either oven. In the case of miele the speed and combi steam ovens max out at 435 degrees and the broiler is not as strong as a full size oven. It could also be an issue down the road for resell as the cabinets would need significant rework to incorporate a traditional 30” oven. That may or may not be an issue for you. The cleaning aspect is another consideration as self clean may not be an option. (I use self clean on my miele Convection oven - 5+ years and no problems). I was fortunate to be able to include a 30” wall/combi steam/speed (all Miele) in my kitchen. If I had a choice I would have nixed the speed and found a place to house an inexpensive microwave hidden either in a cabinet or my walk in pantry (I still have my old toaster oven there and use it occasionally). Since I have a combi steam and induction - I rarely I use my micro.