I belive Ian McDiarmid as the emperor is somewhat superior to Clive Revil's, BUT... I disagree with messing up with the film for all the reasons we have discussed before, so, I was always against having him there. I still remember seeing the screenshot of Ian McDiarmid as the emperor in ESB on AICN (along with Hayden on ROTJ), and thinking "Now this has GOT to be fake"!

What I enjoyed about Ian McDiarmid in ROTJ is how young he was playing that part, and thanks to his acting and voice (and make-up) he looked like a fragile old man (well, sort of). Kinda like Max von Sydow in The Exorcist, you know? It's like "he was HOW old?!" Also, when the prequels came up he was the right age to play Palpatine, so it sort of worked out well.