Yes moves 24 and 25 were terrible for black. When I received the email with ... f6 I almost wrote Bxf6 back without any calculation.
The reason I chose the Qb3/Bxc6 line was that it offered me a very clear middlegame plan. I had 2 concerns:
1. The light squares around my king would be weak
2. My opponent could eaily (and later did) engineer an opposite color bishop game, which had it progressed to an endgame could have been drawn.
The advantage of the system is that with B3, Nc3-a4, Bb2 and Rc1 I can easily generate tremendous pressure against my opponents double-isolated c pawns. Ironically, the setup vaguly reminds me of playing a nimzo-indian (a defense I used to play regularily).