i personally like r/w better, but i will say if you are going for the better pvp class, then r/k all the way...the more fun combo is r/w...
r/k gets EA... 'Nuff said
r/w is fun, but rage is a SoB to manage in pvp, with no white hits or taking alot of small hits, there is virtually no way to manage rage, besides skills/pots, and thats not nearly enough to keep your rage high enough to do be using slash/whirlwind/other elites all the time. however, r/w gets a throw mastery, which adds a wicked slow debuff on throw, which is nice when trying to catch kiting scouts and such(if your not already dead). r/w also gets whirlwind mastery, which lowers rage cost and CD time, but whirlwind is not used much in pvp except on guards and trips, which you could simply just get the same job done with a LB or slash. haven't toyed with poison much in pvp(the r/w elites), so maybe some1 can talk more about that