Saw them in '05 when they "reformed" so to speak and started the Carnival of Sins tour, Vince sucked, but the other 3 were great. The entire performance of "Home Sweet Home" in the middle of the show... oh man, goosebumps. That guitar solo was absolutely soulful. Then Tommy's drum solo, and of course... titty cam. Boy.... good times.
Saw them again a few years ago when they were in Greenville with The Last Vegas (they won some Guitar Center contest, really good band), Theory of a Deadman, and Hinder. MUCH better show than '05. Vince sounded a whole lot better and was actually on-key, Tommy and Nikki were on point (Tommy didn't do his big, elaborate drum solo though, which kinda blew), but Mick Mars was on fire. His medicine for that spinal disease was apparently working amazingly well.
In '05 he was an absolute zombie and BARELY moved the entire show, but hit every single note. 2nd time around, he actually walked around, seemed to have a little groove in his playing, and just seemed more relaxed. They cut the lights mid-show, and all of a sudden you heard Mick chunking away at his strings, then leaned into his Crybaby and started playing 'Voodoo Child', it tapered off into a short solo, then he dipped the tremolo and yanked it back up straight into "Kickstart My Heart".
The encore was "Home Sweet Home", and it was the most beautiful rendition of the song I've ever heard. Closest video I've found that came to it was this: