1.e4 c5 2.Nc3 Nc6 3.g3 Nf6 4.Bg2 e6 5.d3 d6 6.f4 Be7 7.Nf3 0-0 8.0-0 Rb8 9.h3 d5 10.g4

In this line, which is Wells - Gormally (or close to it, anyway), why is 10...d4 not worth a mention?  Seems like an obvious enough move to a patzer, and in fact Fritz seems to prefer it, at least on a quick analysis.  However, neither Palliser nor Lane consider this move.

Wells - Gormally, Gershon - Shabalov, and Spraggett - Leseige all continued 10...dxe4 in similar positions.

My guess is that by closing the position with 10...d4, Black relenquishes all possibility of central counterplay.  The game is thus reduced to a race on each wing, where White has a leg up on his side of the board.  Moreover, White is directly attacking Black's king, whereas the best Black can hope for immediately is to "generate some play" on the queenside.  Definite advantage to White?

But that's just a guess.

@dsanchez:
I find those setups annoying as well. I play the Leningrad Bird and swith to the closed sicilian if needed. So then f4 is already played. I find in those situations the black position very hard to crack. I do not yet have good solutions for it.

1.e4 c5 2.Nc3 Nc6 (I think e6 3.g3 d5 or 3.Nge2 Nc6 4.g3 d5 more precise) 3.g3 Nf6 4.Bg2 e6 5.Nge2 d5 (d6 6.d3 or a6 6.o-o first) 6.exd5 exd5 7.d4 and White has good chances to maintain some advantage.

After weeks of working through Lane's book, and now Palliser's book, and after weeks of trying it out on ICC, I was finally able to trot out my new weapon at the club again this week.

This makes 2 times I've tried it in tournaments.  And 2 times my opponents have played:

1.e4 c5 2.Nc3 Nc6 3.g3 Nf6!? 4.Bg2 e6.

Very disappointing.  Don't these guys read? 

Does anyone else run into this?  How do you handle it?  Most of the main line 6.Be3 ideas don't seem to apply here.  Do you switch gears and play in Open style with d4?  (Seems like Black would welcome this having played classically).  Do you go ahead ahead and launch your f-pawn, even though there is no ...g6 lever?  Do you play f4 with the idea of e5 and a nice space advantage even though your kingside is very breezy?  Or do you stick with your guns and play by rote: d3, Be3, Qd2.

Thanks