Sam, saving mana is a big deal for having a large group. You do save mana. It's NOT a linear progression, though. If it takes 6 lightning bolts to kill a mob you may have times where you shot out 2 sets of 5 LBs before the mob died, thereby wasting 4 LBs. In this case, you'd only save 3x the mana, not 5x. There also comes a point where you can almost chain pull without going out of mana in some cases, especially if you spec for the mana saving talents and keep a mana tide nearby. This applies also to a single boxer. The strength of a 5 man group over 2 is probably more in pure killing speed due to raw damage output than to mana issues.