I wouldnt mind having one of these things, the mags are fairly easy to come by. My only issue with the thing is the fore-end not having anything to be able to mount a bi-pod on in any way but that's a fairly small gripe for most people.
I heard a rumor they are working on making a second type forend but not sure if it went through.
Saving brass for this thing is really easy since seems to just ooze out of the ejection chute while still being reliably expelled. The mechanics of the RFB is really interesting to say the least. I think you got yourself a good rifle.
I'm already surrounded by half-dead brainless people already, the zombie apocalypse would just give me a reason to be productive and get rid of them.