ECO thinks that 14. Ng5 (in the 9. Re1 variation) leads to unclarity, and that White does better with 12. Bxe6, but it prefers 9...Nd6 to 9...Nef6.

update:  I see that Dautov (in the Informant and Yearbook, post-ECO) thinks that 9...Nef6 is preferable in response to 9. Re1, and should equalize.  He thinks that 9. Qe2 is promising, and that the response 9...c4 is dubious.   I haven't done a systematic search (such as ECO plus all Informants since), though.

Hello,

I read with interest the posts in : ''QGA some analysis'' below. It seems 7.Bb3 is giving black an headache. I myself have lost a nice one, recently,  to it : 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.0-0 a6 7.Bb3 b5 8.a4 b4 9.Nbd2 Bb7 10.e4 Be7 11.e5 Ne4 (?!). 1-0 later. I was black and as it is I am looking into 7.Bb3 Nbd7 with hope to transpose to D29 after 8.Qe2. So, 8.e4 being the Killer let me ask if I miss something or do indeed get = after 8....Nxe4 9.Re1 Nef6 10.d5 Nb6 11.dxe6 Bxe6 12.Qxd8+ Rxd8 (It looks safer than Kxd8) 13.Bxe6 fxe6 14.Ng5 Rd3 from the game below : 

([Event "Gorbea mem op 5th"]
[Site "Madrid"]
[Date "2001.09.10"]
[Round "4"]
[White "Gustafsson, Jan"]
[Black "Hernandez Montalvo, Ivan"]
[Result "1/2-1/2"]
[ECO "D27"]
[WhiteElo "2535"]
[BlackElo "2258"]
[PlyCount "68"]
[EventDate "2001.09.06"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "ESP"]
[Source "ChessBase"]
[SourceDate "2001.10.26"]

1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. e3 e6 5. Bxc4 c5 6. O-O a6 7. Bb3 Nbd7 8. e4 Nxe4 9. Re1 Nef6 10. d5 Nb6 11. dxe6 Bxe6 12. Qxd8+ Rxd8 13. Bxe6 fxe6 14. Ng5 Rd3 15. Nc3 Nc4 16. Na4 Bd6 17. b3 Ne5 18. Nxe6 Kf7 19. Bb2 Kxe6 20. Bxe5 b5 21. Bg3+ Kd5 22. Rad1 Rd4 23. Nc3+ Kc6 24. Rxd4 cxd4 25. Ne2 Bxg3 26. hxg3 Rd8 27. Rc1+ Kb6 28. Nf4 Ne4 29. Nd3 Nc3 30. Rc2 a5 31. Kf1 Re8 32. Rd2 Nb1 33. Rd1 Nc3 34. Rd2 Nb1 1/2-1/2)

After 14....Rd3, Fritz calls it =. If so, what is of the fear from this variation? Of course, it's relative, but black position looks indeed solid.

Maybe 9.Qe2 is stronger. Here, an optimum sequence would be 9....c4 10.Bxc4 Ndf6 11.Bd3 Nd6; Black has waited for the bishop to block the d file.

Interestingly, the .pdf e-book from ChessPublishing doesn't agree and state that after 14.Ng5 white has an initiative ( in the 9.Re1 variation). But sadly, ends it there.

Hopefully, that's one more.. one up my sleeve! Or then, you readers, will show the blind spot.