I've read both. MD excludes foods that I don't eat for religious reasons anyway, plus it has 2 or 3 stages with strict dietary guidelines for each stage. NT isn't "telling you what to do" in the same way- she just gives the principles and encourages you to make your own dietary choices. MD has this 40-day plan for what to eat, when, how much exercise to get, when you should fast, etc. Some people do better with the more regimented approach, others prefer Fallon's more laid-back approach.
I personally disagreed with some of his Biblical interpretations in the MD book- it's not a book I'd want to own because of that.