It’s funny you mention Executive Protection where discreet firepower is sometimes a premium, because that was one of the specialized uses I see as still very much valid. With that said, when I was doing executive protection there were a couple of times there I wanted some real hardware just in case. Both times I found an under-folder AK with a couple of 40 round RPK mags in a duffle bag was awfully hard to beat. That’s a whole lot of mayhem in a very small, flat package.
I know of one guy in the industry to plunked down for a Mini-UZI. I have to say, as far as ultra-compact SMG’s go, the Mini-UZI is top notch. The MP5-K was pretty much worthless until they came up with the side folding stock, then it became downright decent.
As for the Thompson, later SMG’s have it very much out classed. The greatest asset of the Thompson wasn’t so much the weapon as the cartridge. For WWII it was an outstanding weapon due to its quality and cartridge (I still say the best SMG of the war was the PPSh-41). But it’s not very small, it’s really heavy and not the most ergonomic thing in the world. But it has cool in spades, that much is for sure. To my way of thinking, there has never been a better SMG made than the Sterling. The Colt SMG on the M16 platform is an oft forgotten SMG that was really outstanding; I give it best of the closed bolt SMG’s; considerably better than the MP5.