Board Thread:General Discussion/@comment-4957813-20131113141215/@comment-26420452-20131113212924

According to me, the Quincy who Medallize a Bankai effectively steal its Zanpakutō spirit away, but owing to some aspect of Quincies' nature which we still don't know, they aren't able to perceive it.

On the other hand, the Shinigami will feel the spirit not being present, but otherwise can use their Shikai. (For example, Ichigo didn't have to communicate all the time with the (now Quincy) Zangetsu in order to use his Zanpakutō).