I had a game the other night and was not a huge fan really - you have to level up to fly and I just found I was getting trounced by people who were flying whilst I was pottering about in a Jeep/on foot.
I also don't like being unable to swap class as and when I please. Picking spawn points doesn't really work either - I seemed to spend all my dead time loading new player's info when dead so couldn't click 'spawn at main base' even when I wanted to.
But it is free
The sooner you get behind, the longer you have to catch up.