My 2 cents -
Aretha is a singer I really loved at one point, but (and I wish it were otherwise) I've gotten bored with her over the years. Really bored. To my ears her "bag of licks" just got smaller and smaller and she became predictable. For me the Columbias and first few Atlantic lps were my favorites. Probably I lose interest somewhere after Live At the Fillmore. As Soul morphed in many respects into Disco or Dance Music Aretha went with it. I saw her live sometime around 1978. the rhythm section with her was ininspired and she was uninspired. I was really disappointed. It wasn't at all what I expected and nowhere's NEAR the fillmore lp in terms of feeling AND a smokin' band.
For a long time I hoped that sometime in the 80s or 90s she would reunite with a good rhythm section (Rainey, Purdie, etc) and get some good tunes, let the musicians blow, and cut a great album, but there was never anything but the most commercial of efforts from her. Couldn't someone of her stature done ONE album not catering to the most commercial interest?
Regarding the Rare 'Retha - it piques my interest. There IS a lot with the rhythm section I dug most with her, but that begs another question - are the alternates just Aretha over the same track that was released or are they alternate rhythm tracks as well?