The Aquia works quite well if it is installed properly! FWIW, Toto is the largest toilet manufacturer in the world with factories in many places ans sales all over the place (including a factory in Georgia). This wouldn't be true if their products didn't work well.
We have four wall-hungs in our community beach house; just remodeled last year. It's the Geberit dual-flush in-wall tank and valve connected to Duravit wall-hung bowls. The selling point was that the wall-hungs allowed us to relocate the toilets and thus rearrange the Men's and Women's rooms without having to cut the slab. Secondary selling point was that they allegedly look cool and allow for easier cleaning underneath.
I guess. I was reading Terry's forum back then and was all for just replacing the existing toilets in their existing locations with Toto Drakes.
After a year of experience with the Geberit/Duravit combos, I don't hate them but I can't say I am a big fan. The flush is sort-of effective enough, but seems to involve a lot of splashy drama for a moderate result. Example: I just went down there and, being a beach house, there were dead flies floating on top of the water spot. Flush. Big dramatic avalanche of water (but no gurgle). Flies still there. Wait forever for refill. Flush again. Still there. Wait. Put a little paper on top. Flush. Flies gone, little wisp of paper visible just beyond bowl. Man, with the Toto it would have been one flush and all flies gone on a dramatic ride to their final rest. The Toto wall-hung doesn't seem to care whose valve/tank you use. I wonder if swapping these for Toto fixtures would improve the effectiveness of the flush.
The bigger problem, however, is that the toilets in the Women's rooms get clogged every time we have an event and they get substantial use. Invariably someone uses and flushes a bunch of paper, and then flushes again before the tank refills. Then they clog. Then all the women have to start using the Men's Room. The clog doesn't occur at the toilet site, mind you, but down the wall at the bend into the main pipe. By relocating them as he did along a wall perpendicular to the old drain pipe, the contractor eliminated the old run into the main sewer line and replaced it basically with a right angle. Out of the back of the toilet, immediately left along the wall to a T at the old sewer line and hard-right and out of the building. When the clog hits, you apparently can't get to it from the cleanout immediately outside the building, because it's up the line a bit and then a 90 to the left while the rest of the line runs straight ahead to the other side of the beach house where the Men's Room is. Three times now, a toilet has had to be unmounted, and several hours spent with the Big Snake. The first time, the very-experienced local plumber I like couldn't get to it, and had to call in his go-to sewer company - $400+. The other times, $49.99 Sewer and Drain came and charged almost $200 with their big snake. I don't blame the toilet per se for this Bad Situation, but I think that it provides a cautionary tale that the perceived flexibility of installing these things shouldn't lead to Big Ideas that ignore what I assume are basic principles of smart plumbing installation. I'm not sure whether I'm exactly right about the precise cause of the problem, or what the fix is going to be, but I'm pretty sure that the contractor is going to have to answer for this relatively soon, and I'm guessing that we're going to find out that no master plumber recommended that these things be installed as they are, and I'm not sure whether we're going to find a simple solution to this problem. (BTW, if anyone has any great ideas about this, please spill...)
In the application that the original poster mentions, it seems to me that he's only saving about 8-9 inches of space in the room. Maybe that's super-important, but if super-reliable is the real desire, than my money is on the Drake or Drake II, particularly as I gain more and more experience with the ones we installed at home. Love 'Em (and the Carlyle II)! Thanks, Terry!