Both of those CD sets above are from the period of the CD version being 2nd class to the vinyl. (And the digital master that made the vinyl remaining unreleased.) The "First Rays" & "South Saturn Delta" compilations (select tracks from War Heroes, Rainbow Bridge, and Cry of Love and then a couple previously bootleg only cuts on SSD) all sound generational next to the original albums. But with the clean copy of SSD and one other track I think obviously sounding better than the old boots. SSD is worth picking up for that.
The big purple box (8 album set) however, sounds absolutely fantastic and I highly recommend! There are only 1 album's worth of reissued tracks throughout and those are from arguably obscure live albums.
I'm still waiting for a proper digital release of the 3 albums (WH, RB, & CoL) those comps are from. (Deutsche Grammophon reissues from the '80s sound pretty good until then. I thought so anyway.)