I liked the Walter Cronkite version as well, it's the first one i experienced as a child. I went on it several times prior to its overhaul in 1994. But the Jeremy Irons version reigns supreme IMO, it absolutely blew me away and every bit the RIGHT way to do a ride improvement. There's just something soothing and epic about his voice that perfectly captured the feel of what the ride is about. His script also flows so well and doesn't kiddify the script. Couple that with the epic music (especially the finale) and the awesome descent sequence, that was one hell of a version. And i feel it's more timeless than what they've done to it now.
I've got nothing against Judi Dench, i happen to like her as an actress. Her voice just doesn't cut it for me in this ride. There's a lot of actors and actresses i really love but feel their voices wouldn't be fit for a certain thing. I also don't like the current script, forgettable music, as well as the pathetic descent sequence (latter of which just isn't going to change with an ipod soundtrack sadly). Still a good ride, just sad considering what once was.
Epcot's Future World overall just really got a massive middle finger IMO since the time i had last visited around 1997 (returned for the first time since then in 2010 and saw what had happened to everything, it was somewhat painful).