After 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 e5 7.Nf3 Be7 8.Bc4 O-O 9.O-O Qc7 10.Bb3 Be6 11.Nd5 Nxd5 12.Bxd5 Bxd5 13.Qxd5 Nd7 14.c4 it seems to me that b5 gives a decent play for Black (and without pawn sacrifice) Anyway my opponent went for 6.Bg5!? and through out of the window this nice preparation !

You are probably right, 7.Nf3 Be6 looks better than it's reputation in theorical books (just bad) but a bit chaotic !
I think that after an early Qc7 White plays Be2!? and goes for a4,a5 and Nd5. He will try to advance on the Queenside. 
The more i look at 1.e4 c5 2.Nf3 d6 3.d4 cxd 4.Nxd4 Nf6 5.Nc3 a6 
6.Be3 e5 7.Nf3 Be7 8.Bc4 0-0 9.0-0 Qc7 10.Bb3 Be6 11.Qe2 Rc8!? the more i like Black's position. What do you think ?

OK, maybe you or Rybka are right (I mean Black is not behind in material or anything, so all lines seem 'playable'), but my personal likings are as follows:

a) The 1st line quoted (early-Be6) looks a tad chaotic to me and with long-term inherent positional problems.

b) My line given with h6 and Be6xNd7 covers for the holes in Black's position and I personally prefer this to Gelfand's ..b6 plan that he uses to stop a5. I also remember Gelfand using this set-up against the 6. Be2 line with an early 9. Kh1 (so I see a preference of his for this set-up).

c) The line you quote in the Short-Gelfand model game: i) I don't see why this position is bad for Black, so can you please elaborate?, ii) If you do like this line, I suggest the following plan (instead of Gelfand's ...b6): 1. e4 c5 2. Nf3 d6 3. d4 cxd 4. Nxd4 Nf6 5. Nc3 a6 6. Be3 e5 7. Nf3 Qc7 8. a4 Be7 9. Be2 O-O 10. a5 Nbd7 and Black can try to equalise by preparing the b5-break and/or the d5-break (e.g. 11. Nd2 b5!). 2 notes:
- If you go for ..b6 or ..b5 you need to keep your Bishop at c8/b7;
- You can also try the ..a5 system which takes away the a5 square from a Knight (if you like the same system vs. 7. Nb3).

hope that helps  

I found another game (Haeusler-Zebisch, 2006, 1-0) where White prefers 11.Na4-b6 instead of 11.a4. Black prepares a d5-break, but I think that the 3 pawn islands for Black, jeopardise any long-term positional advantage. So, your problem is not the 'playable' middlegame, but the 'less playable' late middlegame/endgame.

I personally prefer 7. ... Qc7, which stops Bc4 all the same and prepares an improved version of ...Be6, e.g.:
8. a4 h6 9. a5 Be6 10. Nd5 BxNd5 11. exBd7 Nbd7 12. c4 Be7 13. Be2 O-O 14. O-O and now maybe 14. ... Ng4.