Opinions are personal, so if I say I like it, don't trust what I say as absolute truth.
There's no manual (apart from basic controls layout on the Xbox version) and the starting tutorial barely scratches the surface of the game, leaving buying/selling/modding items untouched, so you'll need to read a lot of guides to the game, on such sites as IGN, etc.
PC version has a lot more control options, especially for groups/clans.
I'm having fun at the start, just playing it like single player, with the odd mission amongst other players/groups/clans doing the same mission.
e.g. Tonight I was having difficulty taking out a camp area, especially the boss mini-gunner.
After a few deaths (respawning costs some game cash called scrips each time) I was gradually reducing the numbers in the camp, when two vehicles flew into the camp, about six players jumped out and wasted all the enemies in a few seconds, then got back into their cars and drove off, leaving me to flick the switch on the radio tower in the camp to complete the mission.
Even though I'm not in a clan yet, I've been revived by other players, so there's definitely a good vibe to the game.
Note: Although there's no monthly subscription, you can spend real money (MS points on Xbox) to get extra in-game scrips, etc., but there's no real need to do that, as you earn enough doing side missions, looting bodies, etc.