Can't comment much on either model other than the fact that you need to keep in mind that ranges need a backguard. I believe this is true for both of the models that you are looking at. You can't install them in a normal countertop installation and keep the island trim that they ship with.

See https://www.houzz.com/discussions/5649974 for a lengthy discussion. If you want to avoid the backguard, you either need to move the range at least 6" away from the wall, or you need to make sure both the framing and the finish of the wall uses only non-combustible materials. That means, steel studs and natural stone (not quartz!) or metal backsplash.

What drew you to these two ranges? Are you getting a griddle or grill?

For backguard, I considered the NXR-PRO brand which comes with a back guard. Does anyone have experience with NXR. Very reasonable price from Costco.

https://www.costco.com/NXR-PRO-36%22-Professional-Style-GAS-Range-in-Stainless-Steel---NXRPRO3651.product.100235026.html

The NXR has some nice features for $2,999. However, I noticed Page 9 of the NXR’s installation instructions requires 10” minimum distance to combustible material from the sides and above countertop. The backguard pictured appears to be 3” or 4” high So you’ll need a taller backguard. I know Thermador offers different height backguards although they are pricey, as is the 36” Thermador range you’re considering.

Shannon_WI, I test drove the Thermador and there was no noticeable clicking. Maybe that was an issue resolved with the new models?

I am not sure I agree with M (a first! I always agree with M).

LOL. Thank you for the compliment ❤

Shannon, let me make an effort to put you at ease again. You said that you have gone years with having a tile backsplash behind a high-powered range, even though it came with island trim.

I believe you. There is a difference between what you can probably get away with, and what building codes tell you to do. When I was younger, I for years lived in an apartment that pushed a gas stove directly against a wall. Since it was just a rental apartment, I couldn't make many changes. I simply decided to mount a glass cutting board to that wall. It helped quite a bit, as I left an air gap behind. And that's pretty critical. That's why the manufacturers backsplash works, too.

Nonetheless, when I moved out, the paint behind the cutting board had bubbled up in places and gotten scorched. But it never caught fire. So, there's that.

So, the same is true in your situation. You most likely will get away with tile on a combustible surface. There might be hidden damage to the wall. Or there might not be. Impossible to tell. And if you sparingly use both oven and rear burners, then there might never be an issue.

But nobody can tell in advance. And building codes have to deal with people doing stupid things. Such as setting your oven on fire (which my dumb ass has managed to do twice in my life) You don't want your house to catch on fire, simply because you forgot what material the backsplash happened to be built from. And if the stove manufacturer explicitly tells you that operation without a backguard isn't safe, then they probably have a reason for that statement.

Consumer Reports tested both the Kitchenaid and Thermador ranges. You might want to check its ratings for $8.