Four Elvis albums were available on Quadradisc in the US: Aloha from Hawaii, Live in Memphis, Promised Land and Today.
Five other albums were available on Q8: Elvis in Memphis, Elvis On Stage '70, That's the Way it Is, Live at Madison Square Garden
Only Elvis in Memphis was available on Quadradisc in Japan.
In a nutshell, everything from "That's the Way it Is" through "Today" are very good mixes.
The four Quadradisc releases are good. Anything from the CD-4 era is generally a good mix. The two live albums are, as has been said, fairly front-heavy with strings, horns and backing singers in the rears, as well with crowd noises. "Promised Land" and "Today" are definitive, go-to albums as far as mixes go, with the exception of the titular track on "Promised Land". Fantastic song, but whoever decided to drown Elvis in a reverb chamber should be drug out into a street and shot. That song is absolutely ruined by the reverb & echo. Strangely, that is the only song effected. Every other song has Elvis front-center and tastefully dry. The vocal reverb on "T-R-O-U-B-L-E" on the "Today" album is so perfect, it's frightening. The mix on that tape/disc is phenomenal. Drums, Bass, Elvis, guitars in the front; percussion, backing singers, keyboards/piano in the rears. RCA was absolutely nailing Quad mixes during the 1973/74/75 seasons.
The two tapes that are the most odd are Elvis in Memphis and Live On Stage '70. I've discussed 'Memphis' in another thread, but 'On Stage '70 ' is also a little strange and again, may suffer from a swapped channel. The mix is hardly discrete with Elvis again in all four channels, backing singers in all four channels, drums and crowd in all four channels, and guitar in one channel and piano in another. On C.C. Rider, the guitar bops around channels like the engineer is suffering a stroke.