Well i had a brief test of the Assassin in the beginning (Obviously since i've never played one before lol), but i have to they i didn't like it.
The Assassins are too squidgey for my liking as a physical attack class, although they would be the perfect PKers, you'd have to know how to play one lol.
I've actually had no problems killing Assassins so far who try to kill me (I'm a Wiz btw). On more than 1 occassion i've been hunting and an Assassin had suddenly jumped out of no where to 1 hit me, which almost all of them fail to do so lol.
Its prob down to in-experience of playing the game that they don't manage to hit me when i can't even see them or even ready to defend myself. But once they blew there cover they soon realised they had serious limitations against me lol.
So tbh i think later on in the game i will make an Assassin for Wars/PK purposes, but for now i'd rather stick to my Wiz