Urgh, I despise the AJAX framework for ASP.NET. I've actually never ended up working out how to use it, it just seems so contrary to my instincts when I try to do AJAX stuff.

They started out with some interesting ideas in the WebForms concept (ViewState, etc) but then kept throwing stuff at it when it became the latest hot thing and.. I hate it. The resulting HTML code from the average WebForms project is just terrible- and the custom controls people develop are equally as bad if not worse. MVC gives total control over the resulting HTML, thank god.