I re-listened to the 2013 album remixes yesterday and they sounded better than ever.
The Tanglewood concert mixed by SW sounds good, a bit uneven, some parts are lost at times, but the live settings in the 60s-early 70s made the recordings generally hectic. The 5.1 mix is basic but perfectly appropriate considering.
The Chicago live is in mono from a cassette recorded at the time by the FOH engineer. It sounds surprisingly okay for its vintage, but it is not exactly balanced. It would probably have needed a sympathetic mastering and restoration to sound its best. As it is, it's a bit rough, but totally listenable and enjoyable. I think it is a more energetic performance than Tanglewood, so that kinda makes up for the sound quality.
The version I had of this concert previously had great video quality, but the last 20 minutes had serious audio issues. It would also switch from soundboard to audience source between songs. I'm guessing because the soundboard was so dry. I'll just be happy without all the crackling at the end. I have the box, but haven't watched Tanglewood, yet.