The downside was Ricky Gervais' constant message of "being famous is a bit shit," obviously inspired by the fact that, although he's still popular, the backlash has well and truly got going (especially after a certain charity concert) and he obviously can't deal with it. The attacks on other comedians weren't that necessary, and having a running gag about his trying to avoid appearing on Doctor Who (when in reality big names are queueing up to go on the show) didn't make any sense, and was a bit of a convoluted way to just get a cheap dig at Peter Kay1. Andy's rant at the end on Celebrity Big Brother wasn't anywhere near as profound as he seemed to think it was, either. Really, the admission that being famous was more important to him than being credible was the natural climax of the show.
Still overall I thought the funny stuff outweighed the self-pity and for the most part this was a good way for the series to bow out.
1And it's a shame to have to say that because I'm not a fan of Kay's appearance on Doctor Who2 myself. The fact that he turned down the role he was originally offered and asked for something bigger doesn't help. The fact that RTD indulged him is a whole other can of worms.
2In the unlikely event that you're wondering where my review of the Christmas Doctor Who is, I'm waiting until I've seen it twice before writing about it, like I always do. Not sure why, of course, since it'll mainly consist of me listing the things I'd like to do to Russell Tovey, but there you go.