Who put your concerns to rest? I have read where people say they've done it, yet never see one picture or journal of this setup in action. That makes me wonder..
The only ones I stumbled upon were either using a Lifegard filter (heavy duty pump and seals, PVC through out) or using stand pipes that rose nearly to the surface of the tank. (which reduces pressure, but looks ugly) Believe me, I really want this to work. I just see the potential for bad things. If I recall correctly I think Tom Barr was using a big Ocean Clear filter under his cube, which is a heavy duty in-line design like the Lifegard. Those aren't built like your standard hobbyist Eheim or Fluval canister.