I almost always play lone wolf, because although I miss the backup of a good squad it's just easier to get into the game and find a fight on your own - and there's none of the waiting around that's involved in group play.
Regardless of whether I'm solo or in a squad, I generally play as a Medic - although I play all of the classes from time to time (Infil least). I used to spend a lot of time tanking, but these days I just ground-pound. It feels like the most honest way of earning xp
As for whether I enjoy it... well... I still want to like PS2, and I generally have some fun playing it - but it's often hard to find fights that are even vaguely even, and PS2 just isn't any fun at all when the odds are tipped too far either way.