In Slate this week:
http://www.slate.com/id/2267342/
Lennon and McCartney did, to use the precious phrase, complete each other. "Paul's presence did serve to keep John from drifting too far into obscurity and self-indulgence," said Pete Shotton, a Liverpool boy who stayed in the Beatles' circle, "just as John's influence held in check the more facile and sentimental aspects of Paul's songwriting."
A lot of it's been said before, but not always so thoughtfully. I also couldn't help drawing a lot of similarities to The Police and other bands where creative tension was (IMHO) what often resulted in such excellent, compelling music.