I beta Aion till lvl 25, it hits me more of a PvE game than PvP.
Few of my real life friends just hit level cap, now they bought a copy for me and forcing me play on Israphel server, Elyos race.
All the dmg and hit/miss ratio has a lot to do with your equipment setup and level. Seems a lot of luck involved, no paticlular counter to anything besides the element of surprise.
best pre-50 pvp - ranger (they get better skills early on in oppose to later level for other classes)
best post-50 pvp - sorc (sheer dmg, crowd control, and an "I Win" button)
Just like any other mmo, clerics, sorcs, and templars will be your bread and butter. any other class will be harder to group and level. There's questing options to level, some of those quest actually gives you decent amount of exp.
Problem with the game:
- lack of buff spells on cleric (enchanters gets that)
- line of sight for heal spell is broken
- lack of AoE spells in game
Anyways, go ahead and ask away, i'll do my best to answer
Edit: btw Stereopony rocks!