The beautiful thing about listening to all these recordings is there are no distractions at all, provided of course you give the time and attention to them. You are forced to sit and listen. And this is especially apparent in the first four albums. You can feel as if the 21 year old Dylan is really in the room with you, playing for you. Thus the mono versions of these acoustic songs are definitely superior to the stereo ones (as previously the guitar and vocal tracks were separated on both sides, which always makes my skin crawl). And because of this, the music comes at you full force. The only issue is that the overall sound may come across as a bit harsh when listened to on the hi-fi system, especially with when you hear the harmonica.
As for the other four rock albums, I was surprised how powerful the singularity of the monophonic sound was. And because they're remastered, they sound much richer than their stereo counterparts (which were previously too thin and dull). Of course I'm not saying that mono is always better in general. It has its pros and cons too; take those '09 Beatles recordings for example -- to really experience them, one must listen to both versions (and there's A LOT of difference between them). Stereo plays with the idea of separated instruments on the left and right channels, but sometimes too much of separation isn't a good thing; you're sorta attuned to concentrate your ears on one channel instead. As a result you sometimes lose that sense of chaos found in the best rock & roll music. There's some unexplainable mystical element found in these mono recordings. You are hearing them the way it was meant to be heard. The best sounding album I think is John Weasly Harding.
The box set is accompanied by a booklet containing new liner notes written by Greil Marcus. Fantastic read as usual. He explains the current importance of mono and also gives some interesting background about the 'sound' situation back in the '60s. This is obviously a must-get for all Dylan fans.