The path system is okay, but I feel it needs a bit more work to really shine. And the regular questing is mediocre.
The combat system works really well though. And the housing systems and instances are where the game really shines. Not only can you decorate your own personal housing plot to your heart's content, you can join a warparty and deck out a big warplot. That is then used in 40v40 battle against another warparty.
The dungeons and raids get really crazy. Lots of mechanics, and some boss abilities etc. are randomly selected each week. And you can capture bosses for use in your warplot!