The open pvp of L2 is just adorable. Every single mediocre mini-boss you need for some crafting crap becomes a reason for massive party-pvp. The only reason I actually played L2 was the pvp... Overlord/Dominator was my class and I wtfkillahpwned as OL
No, seriously, I was actually good
And that is totally missing for me. L2 wasn't a spamfest. You actually need to know what you're doing and react to your enemies and to your partymembers with according skill-usage. That kind of teamplay is another thing missing for me in GW2.