Batman, it's a great game and different enough from the others to warrant a closer look.
Just a few of the reasons I like the game.
RvR has three or four different ways that you can partake in the festivities from the very earliest stage of the game. Since both opposing races in each of the three areas are literally side by side. You can attack a PvP flagged player from an opposing race just minutes after your starting spawn.
You have the RvR instances with differing objectives which can be joined simply by clicking the blinking white and red WAR symbol up top. You get teleported into the instance battle it out, are awarded XP, and Renown which both raise your level. Then when it's done you teleport back to where you stood when you joined.
Then you have the RvR battlefields which are shown as red areas on the map. They have quests or scenarios that your realm has to complete while being attacked by the opposition. Plus other simpler objectives like capture the flag.
There are also random events that are triggered which I've only seen one that I know of. Basically Greenskins began swarming the Dwarf starter area. They had to be fought off and then we pushed into their area. Wish I had seen more... maybe somebody else has and can fill in more on that aspect.
Then you have Public Quests which are scattered all over the zones. Some easy to find others a bit hard to locate. Most well worth the time to play through. You can go into them solo or as part of team either way you gain XP and Renown for your contributions. If you are one of the top contributors you gain an extra bonus in the roll which ends the PQs and have a choice of loot if you place.
It's not perfect but close enough for me. I experienced very few bugs and only a few crashes which mostly occurred during booting of the game.