Not sure I agree. Jarrett's whining is quite understandable -- he had to adjust to McLaughlin's presence more than any other musician in the band. The end result isn't better or worse, just different. Disc 5 sounds a lot like the other discs with guitar added on; by disc 6 the band is more adventurous and starts adopting a more guitar-oriented style.
Some noteworthy parts w/McLaughlin in the band -- the last few minutes of "Directions" on disc 5 (excerpted as "Sivad" on Live/Evil), the magnificent "Honky Tonk" on disc 5 (some of Miles's best playing on this set), the great "What I Say" on disc 5, Bartz's solo over McLaughlin and Henderson's start-stop rhythms on the disc 6 "Inamorata".
Guy