Mono is a waste of time. So is stereo, at this point.
I met an audiophile at the record store, and he has been re-mastering all of my music into 5.1 using Logic Pro. He then presses it onto Vinyl and gives it to me to play on a modified Thorens TD-124 in my special music room.
It might sound silly, but stepping into my music room is like taking a time machine 20 years into audio's future.
...If you insist upon listening to mono though, get that Back to Mono Phil Spector comp.