MP3 itself is horribly dated. If you're only using a PC to play the music and you're using the LAME/ MP3 format, you shouldn't even call yourself an audiophile. It's like calling yourself a movie lover and then encoding all your movies in WMV or trying to make Flash / MNG animations using the GIF format. Popularity of the format is the only reason to use it.
I've used LAME 3.97 to encode CD rips. Unless you explicity tell it not to, it will filter out higher frequencies and resample them to lower ones. (12-18khz depending on bitrate). I know if you tell it not to, you'll get some mad distortion and ringing in these higher frequencies at low bitrates. On the bright side, you can set the slope of the crossover, but only as a percent of the frequency.