The PVP is a mix of World PVP and Instanced PVP. They have scenarios called Warfronts that you queue up for. You basically play in a cross server battle group of 4 servers each with two sides Guardian or Defiant. It's not FFA PVP. The World PVP allows you to summon high level NPCs to help raid outposts and towns of the other faction. You don't technically own these town or outposts but if left unchecked you can shut down a zone to the point that the enemy faction can not quest or level until they kick you out.
Here's the best part about that... the developers recently nixed that portion of the game in lieu of a more PVE friendly setup. The message boards went ape shit and the developers eventually re-implemented the feature for PVP only servers. Meaning the developers are listening to their community and have done so on more than one occasion.
The game class customization is more robust than most modern MMO's but it's not as customizable as AC, nothing will ever be that good again. The game looks like WAR and plays like WoW and DAOC.
I'm currently beta testing with the guys over at SA. They're on Defiant side on Lotham. If you anyone in KoC comes over we should try to make Lotham the PVP shard.
Edit: Oh and no looting, I would like to find a game with the AC system again one day.