Based on McEnroe's TV tennis commentary and his book, I thought he had matured. However, he was a totally immature jerk at a similar Senior roundrobin championship held in April (I think) in the Boston area. His behavior was bad at most of his matches, but he took it to a new level of disgrace playing against an injured Pat Cash. He was extremely uptight right from the start of the match and was so totally intent on winning that he was like a 5 year old throwing a temper tantrum for virtually the entire match, blaming everyone but himself whenever he lost a point. He unfairly and continuously berated linesman for good calls that went against him. What an embarrassment to the sport. It became very painful to even watch him. This was not some premeditated act for the paying customers, most of whom were disgusted by his behaviour, especially the ones who brought their kids. The guy's temper is very seriously out-of-control.
I like McEnroe's tennis commentary and I really enjoy watching him play (when his behavior is in-check), however, I would ban him from playing unless he can clean-up his on-court behaviour.