Does anyone have one of these and know if it works well or badly? I'm looking for something that sits right up against the wall to avoid the dirt catcher under the tank behind the bowl.

here are links to the toilets I'm interested in:

Happy D installed against the wall:

http://www.duravit.us/products/series/happy-d./toilets--c-toilets_useo6q3rqe.html

Happy D for 12" rough in:

http://www.duravit.us/products/series/happy-d./toilets/two-piece-toilet--011201_toilets_93013_useo6q3rqe.html

US Toilet one piece for 12"rough-in:

http://www.duravit.us/products/series/us-toilets/toilets/one-piece-toilet--016301_toilets_93538_useo6q3ru8.html

Any other suggestions for toilets that sit flush with the wall like these?