Yes, that is true of some quad titles from other labels (ABC springs to mind - the Steely Dan and Jim Croce quads are quite 'wet' in comparison to their stereo counterparts) but the ones from the CBS family of labels are almost always much, much drier. The Billy Joel quads are a great example of this, as is Rick Derringer's All American Boy - the difference is not subtle. The only exception I can think of offhand is Burton Cummings' self-titled album, where the quad is wetter than the stereo.
Agree about Burton Cummings (the most glaring example) but not about Rick Derringer. I always thought that Rick Derringer was one of the closest the to the stereo version, but I never compared them directly. I don't know about Billy Joel as I really don't really like his material so I don't have any of his quads, I might go for "Piano Man" at some point or most likely for a DV release, if one ever turns up!
a number of WEA & ABC Quads are wetter than their Stereo originals but a greater number of CBS Quads are much drier than the Stereo, including the Quad of Derringer's "All American Boy" which is significantly drier than the Stereo, with little to none of the reverb or delays or effects of the original mixes. also, the Stereo of Poco's "Crazy Eyes" is a lot wetter than the Quad.
I haven't directly compared mixes but I think that the dryness that you are hearing is because the (CBS) SQ quads were mixed with such extreme separation between tracks. Listening to the DV releases you go WOW at times at other times feel that the extreme isolation of instruments is a bit over the top. They were mixed to sound right played through a full logic SQ decoder. The encode/decode process is not perfect so that random phase shifted crosstalk components abound. That is what makes virtually all CBS SQ releases sound wetter to me. By comparison the stereo mixes sound rather plain, boring even.
