This is going to sound rather critical despite my rating, but I feel like I ought to be rather honest. The basic over-story is pretty good, as is the action and most of the humor, but there was still swaths of text that felt like it was trying too hard. 
 More funny, more witty, more like Color of Magic than Color of Magic. It wasn't just Rincewind, who I always loved. Rincewind reminds me of Schmendrick from LeGuin's Last Unicorn, only he really doesn't have any magic at all. Ever. And yet, his whose sense of identity and action is still totally in line with being a wizard, and he even puts everything on the line for it. I like that. 
 I even liked Nijel the Barbarian and Conina the Hairdresser and the Sapient Pearwood Chest is always a delight, but other than a good smattering of good scenes with all of them, I kept stopping the book and wondering if it would ever get on with it. 
 The adventure seemed good, but it was really focused on the zingers just a tad too much and I got tired of them. Isn't that odd? 
 Even so, it was mostly pretty awesome as Pratchett usually is. :) 
 As an afterthought, I was thinking about Rincewind in relations to Pratchett, himself. I was thinking that maybe Pratchett was Rincewind. As a writer, it's always about faking it until you make it. Keep with the decision and call yourself what you will be. Believe it and move mountains, just like Rincewind. Or Pratchett. :) 
 And then there's also the hallmark self-depreciation, the humor. There was that really big inspiration, that one unique idea that hit Rincewind with great fanfare.... with his companions calling him an idiot right after he expressed it. 
 Pretty classic. :)