We dont know for sure how much the stats increase our damage and magic enhancing, but one thing for sure is that dex and pie give a boost on your damage according to what the dev team posted about stat allocation, i dont think af alone will give better stats in the long run although those sets might have a bonus for having a full set like other MMO's we'll know in a few days now, in my op. i would recomend you always look for dex and pie, remember that bard comes from archer as main so its logical to bet for those stats, the logic that XI had in stats doesnt apply here, they might give you enhancing for songs with pie or dex, who knows.