Thinking of a back to wall toilet, the appeal of being able to mop
underneath a wall-hung seems less than my concern about how sturdy they
are to the wall, so looking at floor standing ones.

Cistern to go behind stud/aquapanel/tiled wall, not got miles of depth
to play with, so don't think I'll find a 9 litre one for extra flushing
power that will fit, thinking of this cistern, which fits in 125mm

http://www.thomasdudley.co.uk/bathroom/concealed-cisterns/vantage.html

Looking at the diagrams on various websites, e.g.

http://static.victoriaplumb.com/images/tec_spec/Arc-Back-To-Wall-Toilet-including-Soft-Closing-Seat-+-Shut-Off-Valve_2377.jpg

they show the centres and lengths required for flush and soil pipes,
obviously there's chance to do a first fit of the plumbing without the
tiling and aquapanel in place, but once tiled, you're working blind for
the final fit, is it really just a case of shoving the loo straight back
on the pipework? I have visions of it being fiddly ...

Anyone fitted them?