I haven't read the Deryni books (or the Muskateers . . . sequels? offshoots? spin-offs?), but totally "yes!" to the comic book reaction. I hate hate hate hate hate it when someone takes a character I adore and suddenly changes them in ways that do violence to my conception of the character. And the more I love the character(s), the less likely I am to tolerate this sort of thing. Also quit reading certain comics numerous times in the past over this.

Was not happy about SEVERAL character developments in BtVS s6, either. If it wasn't for OMWF I'd say that not ending the show over the contract dispute after s5 was one of the worst things to happen in the history of TV-dom.