Yes, top weight matters. Lower top gets the ball into a roll sooner, with usually less snap on the backend. It all depends on the ration of top to side to finger.
A ball with zero side, zero finger/thumb/ and zero top will roll very early and do only what you do to the ball as far as turning it goes.
This is a good combo for heavy oil, as long as you can get the ball through the heads, with either loft, side turn, or oil.
Positive weights (side, finger and top) will usuallu make the ball go longer and finish harder, if it isn't going too long.
Negative side, finger and thumb will get the ball into an earlier roll with less hook at the backend. =:^D