I will take John's career over Andre's, anyday. Interesting that both had motivation and substance problems, yet had great careers.
Agassi has very few achievements to boast over Mac. One Slam more, career Grand Slam.
OTOH McEnroe has 4 consecutive YE nr 1 finishes, more Wimbledon and US Open titles (2 most prestigious Slams), great Davis Cup record and an awesome doubles career.