You see that's what I say! Try both of them out for a while, and if you get bored with one, switch to the other one, and if you get bored with the other one, do another job in a different world or something and just keep multiple characters so you can switch with them when you get bored! That's what I do!
If I get bored with my Assassin-to-be, I train with my Ice Mage, (he's only level 32 but oh well :P) , and if I get bored with him, I switch back to my Rogue and transer all of the stuff I got from my mage such as ores, and stuff and make it a more enjoyable experience (I just wish that I could store more items with the Mr. *instert Asian name here*, so that way it'll be faster and better to transfer stuff between accounts in the same world). But yes, just try them all out and see what you like best and then stick with that, and if you need a rest with one guy work on someone else =D.