Thoughts on the Robatsch (Modern) Defense? I heard from IM Andrew Martin that if you are unsure what to play as Black, you should play the following moves no matter what White plays (not sure I agree with him saying no matter what White plays though).  Those moves are g6, Bg7, and c5 with the idea of opening up the c file and bringing your Queen out to a5 or b6.  Has anyone had any success with this approach?  He specifically didn't mention the Robatsch (Modern) defense, but that is initially what this appears to be.

[FEN ""]
1. e4 g6 2. d4 Bg7 3. Nc3 c5
There is a whole book about this system, The Sniper: Play 1...g6, ...Bg7 and ...c5! by FM Charlie Storey, published by Everyman. It has gotten mixed reviews on Amazon and on the ChessPublishing forums.