I think you worded the question poorly. Non bottomless is a double-negative. Do you mean hides that have a bottom vs. hides that don't have a bottom?

Go with the ones with no bottom. You don't want to crank up your heat source just to get through the hide when they could still easily go under the hide and get to a much hotter then normal heat source.

BG: what works for you may not work for everyone. Especially the majority of newbies who come in here that use tank setups.