Amen to Promoted Pawn's post, TRAINING is the key and NOT fancy weaponry. In the SHTF scenarios, the guy who can successfully stalk and take a deer with a sporting arm (harder than it sounds and I don't mean in stands, w/dogs, etc), has basic outdoorsman skills and keeps his a** in the woods WILL survive... Face it, CQB is a group activity for a finely tuned team, one person, even with some level of military training, won't cut it regardless of hardware.
Speaking of which, how many of us REALLY practice, as opposed to plinking and random mag-dumps?!? The FS2K is a fine weapon, so is the AR, AK, FAL, etc. all the way back to SMLE, M98 and '03. I'm a realist and would not relish facing off with with a really experienced operator of a WWI rifle with my fancy new FS2K beyond the very close range!