Laura,
Perhaps I should preface my reply by pointing out that, along with half the aspiring blues musicians in London, I was the harp player with Alexis Korner. I gave up the day that I saw Paul Butterfield fronting John Mayall, I realised that I was in the junior league and would never make it big!
The live album is really for the committed Butterfield fan. Those of us that believe that he had no equal.
Charlie Musslewhite is probably the current leader in the field, but as far as I'm concerned, he just doesn't hack it.
To me, if I can make two analogies: Butterfield latterly made the harp part of the horn section, where Charlie Christian did the same for the electric guitar in the 30's. To jazz, he was the ambassador of the harp as Larry Adler was to classical music, but nobody has picked up the ball and run with it.
I have 12 Butterfield albums/CD's and, I don't know which two you have, but if I were you: The first Elektra album (Born in Chicago was featured in Blues Brothers 2000) and "The resurrection of Pigboy Crabshaw" for the later work with horns, are the essential albums.
To my eternal regret, when I was travelling down the east coast in '79, I didn't divert to Atlantic City, when I heard on the radio that he was on, to hear the final line up (the one which, notoriously had a punch up on stage at Woodstock).
My cryptic posting was to alert a Mr.Hogan, with whom I had this conversation in a bar in Amersfoort, before the famous spare ribs. On the CD, I would save your money, on Amersfoort in July I wouldn't!
Regards.