Kyrpp is a terrible friend if he didn't give you the basics. There really is not much PVP, but you can "flag" yourself PVP and you can PVP with any other character with this flag. Many of the zones from Live are in this game, but with different content (mobs, loots, quests are much different). The max engage on a mob is 18 and no more than 3 of any one class. This makes for smaller raids which is good in the fact that you are closer to your guildmates, but sometimes makes it hard to fill in gaps for more casual players.
Most classes are about the same with a few changes to each. Slows are no where as powerful as they were on Live, but now you can mitigate the damage from mobs from auxiliary tanking, DoT'ing mobs, etc. Most of the changes are for the better, but it really just depends on your play style and sense of "balancing" on how much you will like/adapt to the changes.
Overall the community on this server is top notch, and the administration does a good job pumping out new content and interacting with the player base. For the monthly fee you pay (nothing), I would say its a pretty sweet deal. Make Kyrpp give you our Vent info and you can stop on and chat with us to find out more.