I've admittedly never used them but did look at them when I was shopping induction cooktops. I really liked the flexibility, they seemed pretty intuitive to use, and sure are pretty. My biggest problem with them (besides the price tag being more than I was willing to spend) was that you can only use 4 pots on them at once. Part of the reason I wanted a 36" was so that I could actually have room to fit 5 good sized pots on the stove. So I guess if you cook with weird sized things it could be useful (and it really would be nice to be able to use different sized pans in the front or back depending on your needs), but it gave me a lot less functionality for a lot more price as I was able to find a fixed layout that works really well for my needs.

I am very interested in these as well. I probably don't ever need more than 4 items going at one time and like the flexibility of being able to use all sorts of sizes.

When I looked at both of these, I was really drawn to the Thermador b/c it had a lot of the nice interface options that also exist with Gaggenau and it's got higher wattage than Gaggenau. However, I ended up with the Gagg b/c I wanted it flush mounted in the counter, and you can't flush mount any of the Thermador induction cooktops. Mine hasn't been installed yet, so I can't speak to cooking quality.

I tried both of these out at a showroom, and they both cooked wonderfully -- I didn't notice any real difference there (not surprising b/c they're both part of the same parent company, so I'd suspect the guts are the same or very similar).

One other thing to realize with both of these cooktops is that they're split left to right -- in other words, you can't have a pan span the midline of the cooktop. So you can have odd size pans, but they need to be on the right side or the left side.