First up I acquired both of Gawain's volumes on the Dragon and Negi's relevant book ( '1 e4 Vs The Sicilians II') at the recent British Championship and it is my intention to look at those on the site in the coming months.
Regards 'NegiRefutes' findings in this particular 9 0-0-0 d5 10 Qe1, I would like to thank him for his submission and hope he is rewarded for his work. I had started my August update but will complete it upon my return from holiday and up before the end of the month, it will now include something on this too.
My initial thoughts are indeed that White could indeed have an advantage in the endgame although with rooks on, two minor pieces for a rook is never straightforward. 'Confused_by_Theory' mentioned Charlie Storey and coincidentally at the British I was sat on the next board to:
Of course not a Dragon but initial thoughts of bystanders watching the endgame (certainly including myself at one point!) led many to believe that facing a passed a-pawn (and with rooks off!), Mark was dead lost. As can be seen, clearly not the case!
'PatzerNoster' correctly observes that Gawain doesn't mention 21 Qc3 in his book and nor does he give an alternative there (i.e. after 14 Kb1) to 14...Rb8.
My quick thoughts are that Black could try to preserve the queens either via 21...Kh8 in 'NegiRefutes' main line or deviate earlier with 19...Bxf8. In the case of the latter White would for example be unwise to try to reach the same type of endgame via 20 fxe4 Nf4 21 Qc3 Bxb3 22 Qxb3+?! (hence the mentioned 22 cxb3 but is then the likes of 22...Re8 23 g3 Nh5 24 Rhf1 Kg7 for example really that straightforward in practice? Objectively I guess White is better but with the queens on, the queenside pawn majority won't have a real impact for a while. ) Qxb3 23 cxb3 Nxg2 as the black rook and bishop are significantly better placed to deal with White's queenside pawns and create threats of his own.
My other observation from practical experience(and I'm sure I'm not the only one!) is that what the computer may have as a 'slight advantage' doesn't always remain that way when humans have to play such imbalanced scenarios over-the-board themselves!
Okay, thanks guys, I'll 'see' you all when I get back.