I'm in middle of a Master's from AMU, it's in International Relations. Despite the relatively lack of prestige from AMU, I've found the classes to be pretty cool and interesting. Most all of it is discussion/forum based with the typical Master's level writing requirements. It's definitely more DoD based in the student population. My most recent class had a couple of O-6s and various people from all different facets of government agencies. Overall it's been a good experience. I'd really love to get one from a traditional brick and mortar school - and perhaps one day will, but so far it's been great, especially with the 8 week courses. TA is not bad either, but leaves a little bit to cover personally.
Also, I'm sure many people will chime in with their experiences in brick and mortar vs online schools. I think that there is a lot to be said for a dude (or dudette) who works a real job and get's their Master's in something that they are continuing experience with job related real-world education. At least for me, it seemed to really enrich the quality of the education by having students, in addition to the professor, that had experience based perspectives. An example of this was a U.S. Foreign Policy class that had range of students who worked with various government agencies that were part of the rebuilding/cultural development in Afghanistan and Iraq, led infantry and special operations units on the ground, worked in command positions, etc. They had a real-time perspective to some of the topics in the class.