I find with defrosting in the microwave you have to do it for short periods, pause, turn the meat,
etc. to keep some parts from heating up while the rest is frozen, even when using the defrost cycle. For a large piece you may as well do it under cold water.
I've used any combination of methods in a hurry, but I've also noticed that long slow defrosting in the refrigerator, if you have the time, makes for less mushy meat or fish--particularly fish.