Well, it, like e.g. the Kavalek variation, is the sort of secondary line which has long been given in books as leading to a slight advantage for White -- which should mean it is "sound enough."

As usual with such questions I would wonder what your rating is, what sort of relevant books you've studied etc.

The Classical Fianchetto with 9...Qb6 (against 9. h3, though that isn't the only challenging move) and the Panno have been well-regarded by theory.  Another possibility is the (modified) Gallagher variation, though it seems to be the consensus (e.g. in a Yearbook article about a year ago) that White should be able to get a slight advantage. 

There is no kingside attack against the fianchetto KID, accept it, and learn how to handle well the strategic positions that arise.

Understanding what white is trying to do and the positions to avoid falling in to are paramount for Black. The fianchetto system in particular demands from Black a good deal of prophylaxis, anticipation and patience, along with the usual theoretical  knowledge and tactical eye.

No one said playing the KID was easy.  ;)

Tops :)

Be like Nunn (and Radjabov as of late) and play the Grunfeld against the fianchetto.  I tried fooling around with the panno but even there white can kill black's fun with stuff like the Qd3 line Avrukh recommends.