My sister just gifted me with the Cuisinart CSO Combo-steam oven and we LOVE IT. So as others have noted, I would opt for a steam oven. Having said that, this cuisinart is a countertop model and it is also convection. I am not familiar with the wall ovens with steam so things you may need to consider are: gaggenau is plumbed and would you be allowed to have that installed? Which of the ovens you listed offers convection with their steam option...and of course, if you have been happy with a standard oven and have counter room (I know you said the kitchen was small), this countertop glorified toaster-oven, steam, convection may be the best of having it all.

The Wolf CSO (combi steam oven) opens down not to the side. I am 5' 4". If the bottom of the CSO was higher than 8-10 inches above the countertop, I could not put things in or take them out without burning myself. Even if you are alot taller than I am, at that height, I think you would need something (oven, microwave etc.) with a side opening door.

I went through the same question some years back. Miele has more features for the $$, so I originally wanted that, but at the time they didn't have a combi/convection steam oven that could take 208V (what I had), so I settled with the Wolf instead. And I must say, I've been really happy with it. It works, it's not fussy. Yes, it doesn't have the color swipey screen the Miele has, but I'm not convinced I miss that all that much. Would I like a broiler? I think so, as it is something I use, but I do have another big oven with the broiler (that unit almost always takes a backseat to the convection steam unit) and I can use that when I'm broiling something, so it's not too bad. I've kept tabs on the Miele, and I've discovered that considering that if you don't get a plumbed unit, the Wolf is more forgiving than the Miele on how much water is in the tank (I'm pretty lazy and never fill it up all the way, and the Wolf lets me still use it as long as I have enough water). If you really want to go into the details about adjusting settings, moisture level, turning on upper element broiler, you'll want the Miele, but if you just want to use it, I think you'd like the Wolf. I certainly don't regret having to "settle" for it at all.

A microwave is not redundant, but strongly recommend you consider a small countertop model. When it dies, it will cost $100 to $200 to replace. With a built in, you may have to have the cabinet reworked to make a new one fit. The small countertop MW will do just as well as a built in drawer MW. If you don't want it on the counter, put it on cabinet with an open shelf ( that makes it easiest to access and replace) or have it in a cabinet with a door to let it hide behind. You won't use it that much, since you will use the CSO for reheating most foods. Warming a cup of tea, or making instant oatmeal is faster in MW, but you will not be using it as much once you get the CSO.