all in what you are trying to accomplish with the scape.
hiding the gyres, overflow, heater and return was a must for me.
part of mine breaks the surface at full water level.
my bta loves it up there.
it's tips break the surface, and i don't mean from a water change.
i have softies, gorgonia's, zoas and lps that are clear of the water during water changes with no adverse effects.