I know on the Outlaw forums there are many people driving a lot of so called "hard to drive" speakers. They are rated to handle 4ohm speakers. I know at one time Bugbitten, who hasn't posted here in awhile was driving m80's with the model that preceeded the 2200. I know they are stackable as well, and if you buy in quantaties I think they give you a discount.
One problem with buying a lot of these is you will have a lot of power cords to plug in.
I don't know a lot about the G topology, however, my understanding is that in higher demand situations, it only takes 2 microseconds, .000002 of a second, to transition from A/B to G, it is inaudible, and allows for them to make a powerful, small footprint amp.
Here is a review of the older 200, they even used one of JohnK's favorite CD's Holst Planets in the review. http://www.hometheaterhifi.com/volume_10_2/outlaw-audio-200-amplifier-4-2003.html
and another from a user over on Outlaw..http://www.prillaman.net/m200_review.html
All of Outlaw amps are built by ATI (this is a good thing) right here in the U.S., per specs given by the Outlaws. However, the 2200 is built oversees in Taiwan by their supplier, again it has to meet their specs and design needs to be badged an Outlaw.