No difference at all, apparently - just more faff involved with making up bottles when you can just whip out the boobs...
On a night, I think my daughter's main problem was tons of wind. We had to bounce her gently while upright, cycle her legs, do tiger in a tree hold, anything to try to relieve the trumps! Formula would just make stuff like that worse, I think - your milk is completely designed for your baby's inexperienced belly. Nights are just crap for babies... and therefore mums and dads too... it's a good job they're cute, eh?