I've spend a few days remaking a number of MiniDiscs of Diana Ross following acquiring newly remastered cds and writing edited versions of the Mp3's from the laptop.
To recap for those who weren't around in the 90's they looked like this and run up to 80minutes and 59 Seconds.
MiniDisc Forum @ Sony
The output stages in particular are limited in how well they can drive headphones well so even when you take a Mp3 intended for one and copy it over to MiniDisc, it sounds better via the MiniDisc than being played on a solid state player. Ironically the best headphone output I have from a solid state device is this laptop but that's hardly portable!
You just have to remember to pack a few discs in your coat or short pockets which is where these 2 albums per disc compilations come in missing off less essential bonus tracks come in. Diana Ross's music is enjoyable on long bus or train rides so having her studio albums from 1970 thru 1980 on just five MiniDiscs will keep me entertained!
My Sharp runs off a single AA cell for over 20 hours too.