The height would depend on the angle the tree branches fire inward, wouldn't it? Even if you can't bend the arms of the the pre-made trees, you could weld little pipes or vanes above them to bias the direction they fire, couldn't you?
Most percs just make bubbles. This one produces multiple streams of froth (the vids showed so much potential), so it looks like nothing else out there. Plus the science suggests it should provide a very high level of moisture conditioning _and_ diffusion (mixing). (And if recyclers are anything to go by, people are happy to sacrifice performance to have a cool visual gimmick...)
The slots in the bottom of the tree prolly aren't actually needed, but since you seem to get them premade I guess there's nothing you can do about that?