Can't speak for Geoff. I thought the remaster was a bit tighter in places.
(spoilers)

Starting with Gilday's "confession" did put the Vatican problem in a more plausible light, but the original start--Michael's letter to his kids in the creepy, ruined boathouse and the Papal Knight investiture scene were good (and IMO needed) atmospherics. Not having Michael keel over at the end didn't add anything--just subtracted from "closure."

My opinion of III is unchanged: A good movie overall but not anywhere near GF and II.