Not listening to the whole thing but from what I did hear it just seems very flat, it has that AM radio feel, buzzy but no depth to it at all. I don't it is an encoding issue, more like someone processed the hell out out if before hand to reduce the dynamic range of the sound; normalized out the loud and soft and then sort of expanded the rest as filler.
If you know the songs/tracks/artist you might be able to compare this with an unmixed version. Overall it just sounds dead IMHO. I would compare it to turning on Dolby NR as on an old tape deck, the tape his is removed but so is much of the brightness of the music. It sounds cleaner but muffled. If you have never had a tape deck this comparison will be lost on you.