Max plays his ass off during the concert, and gives us the first view of a "totally bebop quintet". Prior to this recording all commercial bop records included a "ringer" from the previous era.
I would hope all really serious fans of the era would listen (and chart sequentially) the commercial recordings of the time. I have done this and it's really informative.
I decided the cymbal playing on 52nd nailed it as Sid - that was my call. I still think it is Catlett on drums here though S Crouch and L Schoenberg think it's Max.