I don't like mono in general. It bothers me that the sound is so claustrophobic. I much prefer stereo. Even "ping-pong" stereo from the sixties (drums on one side, vocals on the other) is preferable to mono for me. In fact most of the time I widen the stereo field while listening (on a player that supports it, such as my Sansa Clip Zip running Rockbox), unless it's really overdone ping-pong stereo, to which I add crossfeed (to basically narrow the stereo field a little).
I do find the Beatles mono mixes interesting though, but I'm a massive Beatles fan, and the mixes are frequently different enough from the stereo to be a fun listen now and then.