Catch-up said:
Although I do get why people love the Josh Kirby covers, I could never get over the total disconnect of the cover with the story. It always looked like someone fed him just a few bits of information and he guessed at the rest. Guessed all wrong!
I think he managed to capture the chaos of the Discworld. The Paul Kidby stuff is drawn well but other than Night Watch, they are quite boring. Not as bad as the American covers though.