This is a very different type of shooter. It is not a shooter where you jump in racing around building your frag count like traditional shooters. The map is massive (many many kilometres square) and you can go anywhere you like. So even though there can be 64 players you usually only come across 4 or 5 together at one time.
There is an element of planning involved at the start, such as what sort of kit you are going to take and if you want to build an AI squad to support you. You can also make command decision such as what sort of support you are going to move close to the action (the base can be many kilometres away from the action but you can move spawn vehicles anywhere you like and spawn from them instead).
Mech, Purg and I played for many hours yesterday on a map while we were on TeamSpeak and it was a hoot (and a great learning experience for me). Because it is so open ended you can basically sort out your own objectives as you go. As an example, when we started Mech and Purg quickly made an AI team each and loaded a few into the mobile bases and had the AI drive toward the hot zone. The rest of Mechs AI squad and I jumped into a helicopter and started to fly toward the zone while Purg para-dropped earlier and started to clear one end of the town. When we got there, the mobile bases hadn't arrived yet, but we then slowly made our way toward the town. Mech and Purg were wiping out enemy armour while I was sniping at enemy paratroopers. Etc etc etc.
Even the single player missions are great and there are heaps of user made content and mods.
There is a learning curve and not much documentation so there can be some frustration at the start.
Heaps of fun, though. Heartily recommend it.