Sorry, I am knew to this site and was going through some older messages.
Modern Defendo is a system designed by Bill Wolfe that is a blend of Hapkido, Brazilian JJ, and Thai Boxing. Overall it is not a bad system, but relies, for my tastes, a little too much on joint locking and clinching.
Wolfe makes the clinch, the basis for the defending against almost all attacks in the system. He advocates going into a clinch immedietly when attacked, and fighting from there.
The main criticism of Modern Defendo comes from Wolf's claim that it is derived from the teachings of William Fairbairn who taught H2H to the OSS and British Commandos during WWII. Wolfe has done this for marketing purposes, because none of what Wolfe teaches, is shown anywhere in any book or document that explains the teachings of Fairbairn, including Fairbairns own book, "Get Tough."
I hope this helps.
Mike Att