In the movie I'm currently capping though, Widescreen cuts out a lot more than full screen. I've already made about 200 caps in widescreen though, because thats what everyone said they liked. I guess it's too late now.
Here's examples of the different caps from the movie I'm doing (the color difference is because of my brightness settings):
Fullscreen (http://img2.photobucket.com/albums/v11/Peacefully/Image29a.jpg)
Widescreen (http://img2.photobucket.com/albums/v11/Peacefully/Image143.jpg)

I guess from now on I'll do one of each and compare how much is cut out, and whichever has the least amount cut out, I'll use.