I don't know how much time you spend killing bosses, but I think it'd have to be a significant amount to offset X-bow in most situations.
While I personally tried to use bow, I had to switch-up to X-bow for functionality. I found it had an edge in most situations (grinding, PvP, kiting, GWs etc.) and only pulled out the bow for a change of pace. All personal opinion of course, but that's my two