for those of us still spinning the shiny discs.
based on the reviews it seems the rotel is the more dynamic and punchy of the two, whereas the quad gets the nod for overall fine-level detail resolution.
i currently have the rotel rcd-1520 as my main player now. and i can attest that's it's a very engaging listen, overall. very dynamic player (compared to others i listened to at the time when i decided on the rotel).
it seems that the choice is up to you (unless you can afford to buy both) that you're choosing between a more dynamic presentation with superior low-end OR one that can impart a bit more refined and more subtle detail presentation overall.
i realize all of this is relative, as we're talking about only comparing different cd players using standard redbook cd format as the source.
as i'm still researching different players for making a purchase (for what will probably be my final shiny disc spinner) anyone is welcomed to chime in with any player that they're familiar with that i should probably check out other than the QUAD and the ROTEL which were reviewed here:
http://programming4.us/multimedia/23148.aspx