Very few 5 boxers PvP at that level. I will once I reach 70 on all 10 (obviously 5 at a time). I only know a handful of boxers who do. Most PvE and PvP but are not as optimized as they could be to PvP in the arenas. I would love to hear about people's success though. I can't imagine it is easy, having done some arena combat during the beta - and that was level 60 with much less stamina and far fewer AoE effects.