DEAD. Axl's only sung this a handful of times well live, and it sounds good in the studio because he literally recorded this line by line. In fact, he's only performed it as well as Carrie once (Freddie Mercury benefit). They are grasping at straws, and I say this as someone who does prefer the studio version to Carrie's (...slightly).
Tee's absolutely right. I follow tons of GN'R fans and they were showering Carrie with so much praise. Some of them still are. That's how blown away they were. I've read like five marriage proposals to her in the past few days, too. x) The fans who were receptive to Carrie Underwood covering Guns N' Roses in the first place adored it; the ones who would've hated it no matter what think they hated it. I'm betting the majority of people likely to comment on Facebook (judging by the whole Stones fiasco) fall into the latter category. Luckily, Twitter and MyGNRForum tell a different story.