When it comes to a dual-purpose like home defense and fun it usually will end up being much more fun than defending and for that I'd pick the Scorpion for cheaper ammo and I just personally love pistol caliber carbines. Both would serve well for either purpose though, a 9mm carbine might be a little less hearing damage if you ever have to use it in your home.

Scott, either would excel for your needs Sir. The choice really boils down to pistol caliber vs rifle caliber. I personally would go with the 5.56 Springfield Armory Saint Edge for the widest range of flexibility. Both work at home defense distances but the Saint will do that and more at much greater range and with more knock down power.