There are few if any differences. I believe the PDP 5045 has a cable card slot in the media box. BTW I installed a Pioneer PDP504CMX today and I like the styling and functionallity of it as opposed to the 5045. It takes an optional input card in the plasma itself with no media box. I believe both models share the same "glass". I installed it with a Denon 3805 receiver and only had to run a component cable and a composite backup cable. It all goes through a 2 inch greenfield so I can always add digital video cables easily. I really like the set though. I believe the 5040 and 5041 are the same set. No info on the 5050 yet.