If it helps you in you decision at cap pvp 1 v 1 no outside buffs in my experiece x-bow does better then wiz. Without life control a wiz is basically a chinesse nuker minus the snow shield so dies fairly quickly. (Unless you kb then fear of course.) Im not saying they cant win its just alot harder.
X-bow can hold its own with all the kb and kd without extreme on.
If on the other hand you dont like to play fair and would rather stealth/invisable from safe go with the wiz.
Both classes are euro so dont forget they are meant for team play not 1 v 1. So if you want to job war where warrior and cleric buff you and you run out and own about 15 thiefs/hunters go wiz too. Also works in guild war and FW
So to sum it all up, if you want more 1 v 1 play I would reccomend rogue and if you want alot of group pvp go wiz.
Either way keep the wiz for powerlvl/res as vietboy911 said.