Jup this server is quite balanced, people need to get around the fact that it's not meant to be played solo. Some classes are better at killing some things than others are. That being said I think sins are too powerfull. It's not really fair that a sin can stealthspark a 150 arcane (self-buffed only) before their charm even ticks. (yes this can be done, I know this because I have done it myself.).
On that note I think white voodoo is somewhat OP & so are barbs, not just because my class sucks against them but because when you go out at west the vast majority of people is either sin, psy or barb. This is a fair indicator that they're on the strong side. Archers IMO are too squishy, our damage is a joke compared to pretty much anything and tissue's laugh at our defenses. Though with some apo an archer can still be a force to be reckoned with, purge hurts even if the actual shot doesnt.
This being said this server is quite well balanced, it could use some tweaking here and there but overall I see many varied classes in PK so everything is still viable enough to be worth playing.