i'm not sure what encoder they used, or what settings were used, but the definately is missing something. i didn't catch it at first, but it is definately there. the sid version is "brighter" and "crisper". that very well could be an issue from recording it from a software player also, as kegetys suggested, but i would guess that it is more related to the mp3 compression tools they used.
and i wouldn't say its horrible, and no one would notice the difference unless they listened to the 2 files back to back, specially trying to listen for a difference.