While I like the Excelsior class, I like the Ambassador class too, and the refit look of the B has always seemed kind of pointless to me. Its weird they didn't put the C on there, especially since some of the ships on the list look pretty stupid.
I also like the Excelsior class, but hated the 'pot belly love handles' they gave to the B. It really mussed it the design.
Here's a video on the design evolution of the Enterprise ships (sorry, don't mean to hijack the thread by focusing on Trek ships, but the CGI shown here is impressive for each class).