Well this is more like a mini review since I am beat and still need to do a bunch of work...
The RD-2 simply makes my cd's sound better.
Better how?
Increased clarity, dynamics, and a much darker background. After using the RD-2 and listening, it sounds like the volume is turned up and that music is "bigger" sounding (but not in any artifical way). There is also a change in the timbre/tonality of the instruments (most noticeable on brass). It is a little more relaxed and natural sounding.
I had a few friends over today and they were skeptical that this device could do the things I listed above. I played three separate cd's that hadn't gone through the RD-2 (Led Zeppelin Box Set Disc 4 - Moby Dick, Sam Cooke "Night Beat" - Lost and Lookin', Star Wars Original Score, Star Wars Theme). In all cases the guys agreed that there were indeed improvements and by the third cd they were convinced.
The RD-2 isn't cheap (retail list is $360), but I think it was money well spent. I bought mine from Chris at VH Audio who is currently selling the
RD-2 for $329.99
George