Why do some people keep insisting they are the size of a rifle?
They aren't even close to a rifle, they are generally shorter, much lighter, less recoil, less noise, and less power of course, than a rifle. If you have the Sub 2000 then when folded it makes a nice little 16" long package.
Compared to a pistol they are longer, more accurate (in general), easier to shoot, as easy to add lights to, less recoil, less noise, more powerful (higher velocity hence higher energy).
Methinks the detractors are people that don't own one. Personally I have a Sub 2000 with the G17 magwell. I also have full size pistols (5 BHP's and 2 Witness's) available for home protection (one in the nightstand), SU16 in .223, AR with two uppers, an 8mm FN49, HK SLB 2000, SKS, and a bunch of hunting rifles and shotguns. If I wanted a long gun for checking the house in the dark of the night I would go to the Sub 2000 first, SU16 next. Everything else is in a tie for last place.