Promo Pressings

Are old vinyl "promo pressings" (for D.J. use) sonically superior than their commercial counterparts, or is the only difference the white label marked "Not for Sale"?
Just want to strongly second Kelly's mention of Warner Bros' use of Quiex pressings. (did any other label use Quiex?)
Two recordings that blew me away sonically AND MUSICALLY, that I have on Quiex, were;
Donald Fagen: The Nightfly
Paul Simon: Hearts and Bones
Both early digitals(amazingly) from 82, 83 era. I treat those 2,on Quiex,like fine wine.I preserve those pressings for a special listening occasion. Quiex was high end right from the source. Now if I could only find a Quiex of the debut Rikki Lee Jones, or Little Feat's, Time Love's a Hero, I would, well you know!!........Frank
frank: i don't have a quiex of rickie lee's eponymous album but i do have a 10" promo quiex of "girl at her volcano," which includes "under the boardwalk." never heard a better exemplar of "dynamics." another quiex promo to look for, BTW, is laurie anderson, "mister heartbreak." is there an lp you're especially looking for that might cause you to part with you quiex "hearts and bones"? -kelly
Kelly, I wish I could find a list of just what was produced on Quiex. If for any reason I stumble onto another copy of the Quiex "Hearts & Bones",its yours. (I am sure you are aware of just how great this underrated LP is. The "Late great Johnny Ace" cut is a masterpiece!).
I am familiar and also own the "Girl at her volcano" LP but don't have it on Quiex. Ultra rare to be sure. The Rikki Lee interpretation of "Under the boardwalk", is indeed a gem, and the most interesting version of this great Drifters classic. Now if I could only get the desire back to turn on my system. After the week from hell, I just can't do it yet........Frank
frank: i haven't had my system on this week either. i find it impossible to figure what to play. i'll keep up my collecting, tho. perhaps i'll get out to search through the dwindling number of lp bins. BTW, if you're a paul simon/simon & garfunkle fan, i have some things that might interest you. i bought out the entire collection of a japanese gentleman who was a charter member of the s&g fan club. several "japanese only" box sets and single lp's. great stuff. all first (and only) pressings, equivalent of promos. -kelly
If you ever get the chance for these three grab 'em as the sound is stunning- Hendrix/Electric Ladyland ( equals or betters UK Track pressing)Derek & Domino's/Layla (levels are higher) and Dylan's/Blood On The Tracks (the best harmonics if not pressing). Has anyone heard of a Neil Young Harvest as wlp? I second the comments concering Quiex, wish there were some Steely Dan's on it. (BTW-Katy Lied is pretty good too!).
Does anyone know what Audioquest used?I hear the Doug MacCleod Come To Find is excellent. I want one.