As I'm only recently discovering, there's a rather large difference between The Beatles' albums as released in stereo and the albums as released in mono. The more I read, the more I'm finding out that the mono versions of several of those albums (Rubber Soul, Revolver, Sgt. Pepper especially) are more like "authentic Beatles canon" than their stereo version counterparts.
Here's a quick quote from George Harrison (from the Anthology bonus disc) that I found interesting:
"When they invented stereo, I remember thinking 'Why? What do you want two speakers for?', because it ruined the sound from our point of view. You know, we had everything coming out of one speaker; now it had to come out of two speakers. It sounded like ... very ... naked."
Check out this post at The Beatles Rarity for even more information: "... until 1968, The Beatles placed much more importance on the mono mixes of their recordings, not only because that's what they were most used to and what sound they often preferred, but also because they knew that's what most people were going to hear."
