i absolutely agrgee with the other two, rebounding is important on every position, the more the better. but in my opinion, to really use this as a missmatch your guards rebounding should be 2-3 lvls higher than your oponent's (at least for the players stats, not sure how it really effects the game by boxing out etc)
engine is a bitch here. my regular starting pg has reb 6 and goes for 3,6 rebs/game in 29,6 minutes. my sg and my double-backup have reb 2 and 3 and go for 2,7 in 33,5 and 2,2 in 30,7minutes respectively.
to be honest, i dont see a HUGH difference here, given that my pgs salary was around 13k less(which is over 20%!) with reb 2 instead of 6.
but again: that are only the players stats, not sure how it really effects the game. guess there is a reason why this skill is expensive on every position ;-)