I honestly don't think either Naruto or Sasuke are done showing off their powers yet. For Sasuke: He hasn't seem like he has used his Yin Seal at all IMO. Naruto has shown a little of his Yang Seal but we haven't seen him be too versatile with his TSBs.
IMO, by feats it's Naruto >== Sasuke. Naruto may be slightly better by a margin but Sasuke's arsenal is dangerous agaisnt Naruto, and although they both have a lot of counters to each others' arsenal, it comes down to who pulls off that lucky trick and makes a better opening since they both know how each other fight. Whenever their fight happens, the victor will of course be by a slight margin. It would be terrible writing for Kishi to have Naruto or Sasuke neg diff one another in the final fight.