Former Guns N’ Roses drummer Bryan “Brain” Mantia – who was a member of the fold between 2000 and 2006 and played drums on the majority of “Chinese Democracy” – said he has regrets about not sticking around long enough to be part of the ongoing reunion, explaining on Appetite for Distortion (via Alternative Nation):
“I guess it goes back to what you said about versatility, I think that’s what I’m proud of.
“People can say, ‘He played with Tom Waits and made that  ‘Real Gone’ album, and shit that was badass; he played on Chinese Democracy and that was badass, and he was on Primus’  the ‘Brown Album’ and that was a sick sound and rad too.’
“I guess in the end, I’m proud that I didn’t stick with one thing, and kind of just went with my heart when I kind of felt like things were burning out for me, and I couldn’t give it 110%. I felt like, ‘Well, maybe it’s time to move on.’
“Now financially as I’m getting older – I don’t know, would it have been great to play with Slash and Duff? Fuck yeah.
“I mean, I wish I was on that, because I really feel like that’s the real deal, and I would have loved to have played with them on that thing. So I guess if I would have stuck with it, I would have done it.”