I don't know how White proves an advantage against the ...Na6 lines these days, they seem to be doing very well recently.  I have played the White side against this variation several times recently, and I really don't see any advantage for White in the c5 sacrifice lines, particularly the positions where the Knights are exchanged on c7 or where Black sacrifices the exchange.  So I would tend to agree with Gallagher that such positions are = or unclear, rather than +=, and this conclusion seems to be borne out by the available games.

I feel much more optimistic about White's position in the Bayonet Attack, although this could have more to do with my style than anything else.  Still, I do get the impression that Black is still under some pressure in certain lines.  Once again, recent games seem to support this impression.

If I had to summarize the two lines in a few words it would be as follows:

The Nc6 line is sharper, well-suited for attacking players, and requires knowledge of a large amount of theory.  Black is under a little pressure in the Bayonet Attack, but is getting closer to finding satisfactory answers against it.  All other variations after Nc6 seem okay for Black at present.

The Na6 line is more positional, and is well-suited for players who don't want to learn a huge amount of theory.  Whether White can prove any advantage after Na6 is currently an open question.

If I were going to play the King's Indian as Black (which I used to do many years ago, but without knowing much theory) I would choose the Na6 lines without hesitation.  First, more time would be available to study other variations, so a complete repertoire could be learned more quickly.  Second, I could always pick up the Nc6 lines later if problems arose in the Na6 lines.  Third, the Na6 lines do not appear to be having any serious problems at the moment, and are proving extremely resilient.

Those are just my thoughts, as a player of the White side of the King's Indian.  Others might reasonably disagree with them.

         - Geof

I personally believe that the Bayonet Attack isn't that scary, but that it just leads to relatively unusual positions for the die-hard KID player.  Obviously this can be cured with practice, or you can stick to the user-friendly 7...Na6.

Regards

Paul Hopwood

When reading questions like this, I always think of the comment of Tsjigorin: what is winning for White today is refuted tomorrow (very free quote). Another authority who scoffed at the truth in openings was Alekhine: "Madame la theorie ....".
As soon as we all know the truth in chess, we should switch to Go.
I do not want to insult, I only want to explain why such questions are impossible to answer.