Best birthing pool?

[PreggoEggo]

I am looking at buying or renting a birth pool for home. Are heated ones better than non-heated? I have a smallish conservatory and was hoping to put it in there. do they take long to fill? and is emptying a nightmare?

I used birth pool in a box (but bought second hand)
takes a while to fill but kept its heat OK while I was in there, or just top up with more hot water if you're in there for longer
inflatable sides and base comfy for sitting/kneeling
I've got no experience with rigid/heated ones so can't compare
Emptying not a drama, DH got a length of hose and started it syphoning, then left the hose out through a window down the nearest drain (may need to sieve out any lumps first)