Well, you are aware that EOS cameras do something before the mirror goes up, right? And various EOS cameras do a better or worse job at metering or autofocusing so if you care about those things then you care about which body you get. After the mirror goes down they also advance the film faster or slower which may or may not be a consideration for you. With AE/AF bodies they are not simply light tight boxes.
Originally Posted by mr rusty