Yeah with the second formation i meant to say 3-5-2V, i only listed 10 players there, oops.
Only problem with 3-5-2V is that, whilst it covers you more defensively, flank attacks are less effective as you won't have a DR/DL supporting your wingers.
I've always gone attacking, no matter what quality the opponent's team are, but that's because I've usually got strong ST/AML/AMR players and that's the style i prefer, but a few people like to play defensive, forcing counters against stronger opposition.
Offside traps work well if you play with 3 at the back too.