Bigger is good, of course, but only if the quality stays high. Kotor is already criticised for too many long, empty corridors, and I wouldn't want Kotor 3 to turn into a hack'n'slash game. Some of the planets in Kotor 2 could certainly have been more substantial though, Korriban in particular. You could have one larger location or two smaller locations - I would prefer the former, I think, but you could have a variety as well.