In the first game, after 8.c3 I think this hits hardest: 8...cxd4 9.cxd4 (white is too cramped right now to do anything else) 9...Bb4 (preventing white from consolidating with 10.Nf3) 10.O-O Bxd2 11.Qxd2 (11.Bxd2 drops the b-pawn) looks promising - white remains tangled, while black can play ...Ba6 to take out another defender of d4 and can take advantage of the delay in developing his knight by Ng8-e7-f5. Giving up the dark bishop matters little since black can always open the center.
In the game, white could have played 12.Bf4, a typical Tarrasch plan that cuts the bishop out. Black should still be fine (an exchange variation by white is never going to be too threatening, but white has no clear weaknesses and has the better pawn structure. 12.Be3 was probably played to gain a tempo, but it improves the black queen more than it does the white bishop.
Today (and yesterday) I tried to get away from ...Nf6 against the Tarrasch, as I was not yet fully satisfied with the positions, and wanted to try something different...so I opted for ...c5.
I believe these ideas were discussed before as the right path, but I was not ready at that time to look into them. Now that I understand the French a tad better, I decided to give them a whirl.
I was reasonably satisfied with my game. I am certain there are some spots I can improve on, but I wanted to ask some feedback from others in the group, if they have ever essayed ...Qb6 in these lines. Here is the game.
I felt like I played decent in the game for my rating, and considering the position. Now, for that other ...Qb6 game that is in my database...
The only win after ...Qb6 was this game, between two masters.