Probably only Paladins. If you don't have trouble holding threat with a +0 relic,the extra stats (mainly VIT) from getting AF2 chest would probably be more beneficial overall.

DD classes and healers should go for the +1 relic though for the most significant boost in damage/healing, though I could be wrong.

On a side note, I went ahead and +1'ed my sword anyway since I really wanted the shiny glow.