I don't have those Miele products, but can comment on cooking with a small oven. I have a GE Profile Twin Flex -- two small ovens in the space of a standard single. The larger oven of the two is only 2.8 cu ft. I can easily fit a 20 lb. turkey in it, could probably fit a 22 pounder. There was plenty of room for a 5 rib roast at Christmas. It bakes four 8 in. cake pans, a tall chiffon cake, or two half sheets of cookies beautifully. I use the upper oven if I need to make a third sheet of cookies. You could use your speed oven, I think, for extra baking capacity if needed. My 12 quart stock pot with lid fits in the oven for simmering stews & soups & braising. After a year and a half, I've yet to wish I'd bought a standard 5 cu ft oven.

I think you'd be surprised how capacious a 3.2 cu ft oven is. I find my small ovens to be super efficient -- no wasted space, no hot spots.

Does the warming drawer have any kind of cooking functionality? Some do.