Done it a few times, it relies a little too much on people being good sports whereas Paintball its a little bit more obvious that you have been hit.
The guys (they are all guys) out here take it very seriously, you can get some real hardcore stuff.
Its fun, doesn’t hurt that much (wear goggles at a minimum) and I found the indoors stuff (close quarters) is great fun, very quick short sessions, not so keen on the outdoors sessions as it turns into a sniper game.
Have not done it in a while as a found it not as much fun as riding a bike, plus I couldn’t take it that seriously.