If I watch a gig of this size live or on DVD I have to compare it to the greatest stand ups that I have seen.
Gervais is hilarious in virtually everything he has done from his segments on The Eleven O'Clock Show (which also launched Sacha Baron Cohen's Ali G), The Office / Extras, his radio show on XFM (the best times I've had in traffic) and his online podcasts.
As a stand-up, I don't think he stands up (exuse the pun) to the great comedians who have hit upon gold (by genius, by luck, by hardwork or courage) the premier list of comics include - Lenny Bruce, Bill Hicks, Chris Rock, Sam Kinison, George Carlin, Eddie Izzard and last but not least Richard Prior.
Gervais's gags are more than adequate in that they service a chuckle, however stand up is more than gags, the greats are more then simply joke machines, they are jesters, actors and stylists. They play with their audience, feeding of them, knowing when they are pushed to the limit and when more leverage can be obtained. Every facial expression, every in-flex in their voice contributes to the projection of the gag.
I don't think Gervais has these skills. His most irritating points are his high pitched voice at inappropriate moments, laughing at his own (relativaly funny) jokes and a lack of any real stage presence.
I have followed his career for a long time (he's pretty much unavoidable in the U.K) and think he is a genuinely funny person, however for a tour the size of Fame, I believe he needs to get on the circuit and hone his act for many years before it is charged to a paying public.