Fun the first few hours, total boredom the rest.
One of the things that disappointed me was the lack of vehicles in a Battlefield game. There are 3 or 4 of them. A tank, a plane and I think 2 cars. This can get fairly boring and accompanied by the limited class selection (3 classes, 2 of which are practically identical) the fun is quickly snuffed out. Battles are really slow-paced and monotonous and almost always end up with the guy that bought the bigger gun winning. Other than that you'll just end up getting knifed by an invisible Commando. The maps are generic and linear and don't offer a lot of strategic opportunities other than just running down that same road again and again.
Then again, it's still worth downloading (unless you covet your memory like your baby) and is worth it as it's free. You might just end up enjoying it if you spend some time gathering friends to play and trying to RP or something lol.