I got my Guardian to lvl 24, and managed to finish the 'beta' personal story.
I'm not going to mention problems that have already been mentioned, but the main issues I had as a melee, was basically down to respawn rates. There were a couple of areas, where I'd just killed an NPC, moved 10 feet, only to find a replacement had already spawned in it's place.
Another thing I had noticed, if a NPC was chasing someone it would often change targets and come for me, when the person it was chasing was merely running past me. That way leads to griefing.
Overall, I did enjoy myself, just wants a few tweeks here and there.. toning down the incoming damage slightly, changing the respawns, and thinning out a couple of the mobs.
Can't wait for the next event.