I found HDTracks a bit disappointing -- overpriced and somewhat overhyped. Some albums were duds at hi-res (e.g. Abbado/Berlin, Beethoven 9th), a few others sounded good (e.g. Susanne Abbuehl's The Gift, Gardot's The Absence). Haven't tried other sites (see link below). But for me, ripping CDs to FLAC or WAV and playing them back on my BDP-1 and speakers, is bliss, next to playing the CDs themselves. Bottom line: it can be hard hearing substantial improvements on "hi-res" 24-bit files vs. 44KHz/16-bit. Maybe more "air". Just my opinion.