I have only handled them and spoken to the Flodman folks at the SHOT Show a few years ago.
Interesting concept and a very modern design. The "hinge" that they use is now being used or very similiar by Remington(?).
One cool thing is that you can get Damasteel barrels on a Flodman gun.
Overall it struck me as a very good and durable gun available in many rifle calibers to go along with the shotgun barrels. They are expensive and the stainless steel finish put me off since I like traditional blued guns.
All of the above is just opinion because in their price range a Flodman gun won't reside in my safe any time soon.
If you haven't done so yet Google them up, they have a pretty good website.