This is a Duravit Vero toilet.
http://www.duravit.us/website/homepage/products/product_overview/series/vero.us-en.html#filter-toilets
The tank is inside the wall. This is the same type of system used in commercial applications - so they do flush well. A popular in-wall carrier system is by Geberit, where you can find the specifications. The toilet and tank system are more costly than a typical toilet and more costly to install. In addition to great looks, there's something to be said for having an open area on the floor for easy cleaning!
- RF

I have encountered these at various hotels over the past few years -- they seem to be used outside the USA more often .. but one reads negative reviews regarding some makes. So ... my question was somewhat more focused on the particular toilet that you used.

I used Duravit in my city place -- the one piece floor units are cool to look at .. but don't flush as well as the ToTo toilets I had previous .. and the USA customer services is lacking. Toto -- uses a different unit that they make although I have not found anyone who has installed one.

The Geberit carrier looks to be companion to all the european makes-- so i'm sure that is the unit I saw installed and they worked well .. or at least I can't remember having a problem.

The square toilet would fit into what i am designing for my new baths .. and having them off the floor is a real plus.

This is the same type of system used in commercial applications, they do flush well...