"The Fillmore Concerts" sounds tinny, imo. The mix is weird, too. Well, the two are related, I guess. The Deluxe Edition, IIRC, keeps everything in the original order, then the bonus tracks. That's the one to grab, imho.
I bought the Filmore Concerts CD in the early 90s and was my first introduction to the Allman Brothers along with First Set. I didn't even find out until a few years ago that that one wasn't the original release.