| I think there are probably a million other variables that affect the sound as much or more. That said, maybe if you took two identical basses from the same maker, same tree, etc. Only one round and one flat, you'd hear a difference. but otherwise... Just a matter of looks and feel. I like flatbacks better, but it's purely subjective. The roundback is arguable more structuraly sound, so that might give it an edge... | 
