User blog comment:SilverRain/Ichigo's True Strength/@comment-10961564-20130630094632/@comment-11051098-20130630111307

Well, his new Zanpakutô is made from an actual Asauchi which he never had, so even though his true power is still Zangetsu, the physical manifestation of Zangetsu (the actual blade) is completely new. So I think it's obvious that like the Shikai, the Bankai too will be completely new. And he could also have gained some new techniques from his new Zanpakutô.

I too think that the power level he gained after the Dangai training might be the level he's at now, with his full power. Seeing as how strong he became then, defeating the already ridiculously strong Aizen with no efforts at all, I think that's how strong we can expect him to be now, until we get to see his full power in battle.