From going over reviews it seems like people have some problems with the water level and skid marks though so probably not ideal.
As a general rule, the in-wall washdown flush models are just a different animal than your basic toilet. The starting water level in the bowl is lower because it isn't needed for the siphon the way it is in traditional toilets. Any low-flow is going to have less water in it to start than the old swimming-pool-of-water that the 3.5+ gpf toilets had. So, absent the swimming pool, sometimes some sticky stuff is going to contact the porcelain. In a washdown, probably more so. But in a washdown, a prodigious amount of water flows down the sides of the bowl, which tends to loosen/eliminate what's in there and stuck to there.
If people are used to the washdown flush (say, Europeans or whatever), you don't see the whining that I see on some other sites. "I bought this totally-different-type-of-toilet because someone told me that a wall-mount was cool, and it
isn't the same as my regular toilet!!!!! DO NOT BUY!!!!!" It's kinda silly.
We have 3 wall-mount bowls with in-wall tanks in our beach house. We started with the Duravit bowls, and have since replaced most with Aquias. I think the Aquia is a better flush than the Duravits, and looks better to me and has a little more water in the starting position. They work great. They're different than the Drakes at the house. Duh. But we like them. And skid marks aren't for us any kind of problem. And apparently most people who have come to the beach house haven't carefully-stared at what's in the bowl and how the bowl works. They do comment with interest/curiosity on having the two pushbuttons on the wall (Geberit tanks). But they haven't obsessed about what went in and whether anything was left behind. They just used the thing, figured out which button to push, and went about their day, often complimenting the renovation.