Steely Dan CDs

I would check out the Steve Hoffman forums for this information. Undoubtedly there has been a discussion related to this.

Look for the thread on Hoffman forums that compiles all the SD findings into one place.There are many masterings for each release, and a hierarchy of best sounding ones. In my opinion the older MCA releases are best.

Edit: this is the thread.
http://forums.stevehoffman.tv/threads/steely-dan-cds-different-masterings-the-summary-thread.561226/

I have found that, for the most part, the MCA recordings are superior to what followed them. Gaucho in 5.1 is a must have if you have surround sound--and its 2 channel is great too IMO. Having said that the Gaucho MCA is very good. Can't Buy A Thrill UICY 2122 SHM-CD and UICY-25036 Countdown to Ecstasy SHM-CD sound more detailed than the MCA IMO. Cost more too. I would buy them again, but I can imagine others would disagree on whether the difference is worth the price. Of course, Steely Dan's last two albums weren't MCA releases. Especially on Steely Dan albums, following dr loudness wars data and selecting the version with the largest dynamic range yields the best recording--even when comparing SACD to Redbook. I have done this exercise--so you don't have to :-)
The great news is that a less than stellar Steely Dan recording is almost every other artist's best record SQ wise. They lived in the studio listening to minute details and it paid off with a SQ catalog that is hard to beat.