Suck or blow... and where's the best spot to do it?

You want to draw cool air in down low to the ground and expel it at the highest place. So place it to blow out. As for placement? Where would it be used the most? Put it there. IMHO the bedroom is probably the worst place to put it. The noise at night might be really annoying for you.
Mine is in the living room and we use it about as much as the AC unit.