Cool review.
I think the "double the size of 1988" thing is more a statement of how insanely skinny he was in 1988 than how fat he is in 2006... look at the picture... or if you just saw Axl in the street somewhere.... would your first reaction be... "Wow. What a fat ass!"!?!? I think not. There are so many more ridiculously fat lard asses in the world than Axl... many of them music critics.
Yes, I would totally agree with that statement. But I wouldn't say that he was much different in the 1980's from other singers out there. That was part of the stereotype created by Mick Jagger, Jim Morrison, Robert Plant, Steven Tyler, etc. in the 1960s and 1970s. Basically, it was very difficult to be a front man of a rock band if you weren't pretty skinny.
Axl now is what I'd call in "good shape" especially for his age (Plant was in worse shape at the same age, and look at Vince Neil and others out there). And when you consider how fat the average American is, Axl is not just in good shape, he's in GREAT shape.