The bad guys aren't really bad; the good guys aren't really good. There is none of the humor, sensibilities, or character of his first three books in the series.
Mr. Asprin can be a fine, funny writer but has a tendency to lose both control and track of his characters. What started out as a fine funny romp in 'Another Fine Myth' has settled down into formulaic nonsense in which the characters don't have character, they have stereotypes. The characters aren't flawed, they are plot points. No exploration of the humor of the human condition, just something else to resolve to extend the text a few pages.
What could be interesting interplay between a not quite mature or worldly boy wizard and a way too worldly Businesswoman Bunny is completely... well... nothing. There is no there there. Tananda has been relegated to a set piece (where is the fiery whimsical assassin who said "Bark at the moon, Istavon"?). The rest of the guys remind me of Michael York's Basil Exposition in the Austin Powers movies. They are simply there to inject or resolve plot points that Rob didn't have the imagination to deal with properly. Also, when did Ahaz become Yoda?
The whole series died somewhere during `Little Myth Marker' and perhaps should have stayed dead.
Let the flames wars begin!