Andrew has a denser sound on the soprano than say the Coltrane-school sound. (It's a curved soprano too, which may be pertinent or not). Also he's playing less rapidly and fluidly here than the other soprano players on this set. It's obviously not his primary axe.
I've listened to the first two discs. I love them. I've always been a fan of what was released on "One on One" and the remainder of that material is fantastic here. I don't find the aimlessness at all, it's to me just the way Hill is and how his music segues from theme to theme, place to place. I've really enjoyed hearing the trio material as well, I love Hill in trio, and adding in the organ and that one outburst of soprano, just adds a new level of fascination. Robinson on drums adds interest for me as well as he has a differnt approach than the other drummers on Hill sessions and I like the approach and the very fact of difference.
Sound is wonderful. Addey's mastering seems to really allow the instruments to speak. McMaster's seems to add a sheen that homogenizes a little bit (and thins out the sound to my ears, more "digitally" sounding, I'm trying not to trash his work, but I'm always disappointed when he's the digital engineer). Addey's mastering here is a definite PLUS! Natural, full sound.
I've had to take a break before going back to this set. Truly powerful music.