Wow cool space gun and very cool pants.

I couldn't afford one and even if I could I would not be allowed one but that just makes me want one more. I really like the whole pistol calibre carbine idea.
Low recoil+ good accuracy in the ranges they are meant for as well as cheap ammo.
I was considering the budget version a Hi Point 9mm carbine. It's like comparing Timex with Rolex but it would make a great plinking/fun gun and would also be a perfect spare in an emergency for the wife or friend who was not into guns.

The best anti armour round legal in the US is the surplus 7.62/25 subgun round for the CZ52 or Tokarev. The CZ52 has a very cool roller delay breech and is a great deal. It is the Subgun ammo I believe the polish stuff that is the best anti armour round. It is also US legal and cheap like borscht.

The only problem with something as cool as HK's and PS-90's etc is how much attention they attract. I prefer something wood and not threatening like
a pump or semiauto 12 guage or a .357 lever gun. My only rifle is a .303 Parker Hale hunting rifle which is about as non-threatening as you can get and still
be a centrefire rifle but because it is built on an Enfield action it holds a 10 round mag(every other rifle in Canada is stuck with 5 except the garands8)and is fast and smooth.

That full auto shottie looks pretty cool though.