i buff when we start. but i have all the pips for medic. i can still buff a few people and be ok at the time i need them. i agree though, some people just buff for xp. i will use all my buffs if the timer is about to end though, naturally 
i hate it on maps like CC when i see soldiers running up the little bridge bit near the gate and ignoring the gate. thats why i generally play with jack of all trades character now as i can do everything and have some toys for each class
