does it support a high played team?
Planetside used to be a massive game, with 3 empires supporting around 200 people on each team, on any given continent, with vehicles / aircraft / mechs battling for supreme control over a world called......ahhhhhhh crap I've forgotten, I was foolishly going to say "Azeroth".... Anyway... yeah, it was a consistent world so people were still fighting when you logged off and you could jump into the heavy action and make a difference from level 1.
The idea was awesome. Sadly, the game is dead now - it used to have 3 servers, which have now been merged into 1, located in the Eastern parts of the United States I think?
It's worth a quick shot, to see if it's still alive 'enough' to satisfy your needs. I tried it not so long ago, and it seemed there were around 70 in each Empire which was decent enough, but obviously having experienced it in it's full glory it didn't feel the same.
I hear they're talking about a Planetside 2 though, so that would be definitely something to look for. That being said, the servers they have can still support the massive games they used to have - but as the game is just plain dead, I don't think it gets the audience it used too... people just left, as the game got too old - and the developers just started to drop off the face of the world with regards to decent upgrades to the game.
Hope this helps!