I walked into the theatre fully expecting and eagerly anticipating the type of offensive, edgy humor Silverman is known for. And while there were certainly some great jokes (and songs!) that had me bursting out laughing, the rest of the movie only raised a smirk and an occasional chuckle. The ending felt particularly flat.
Some jokes just weren't creative enough to be funny, and I'm guessing Silverman hoped the shock value alone would get laughs. When you're sitting in a packed theatre and a "funny" joke/moment comes up, and you can only hear one or two people discernibly laughing - sorry, those are pity laughs. And there seemed to be quite a few points in the movie where this occurred.
So while I was walking out of the theatre thinking of several funny lines, as a whole Silverman's stand-up was so-so. I've laughed much harder and longer at other comedians' routines.