I've got a KBI import 9mm. It's great for a collector because it's as close to the SMG as you can legally get. However, it's kind of silly otherwise as it's an overgrown heavy poorly balanced pistol. Sweet as SMG, weird as pistol.
Don't expect a domestic producer either. The Italians make some complicated stuff, and you don't want to see the results of a Hesse attempt at production.
For the record the Spectre has a few unique features:
1. Sinusoidal Rifling (probably misspelled). A verson of poly...
2. Decock leading to double action. When the decock lever is pushed, the striker runs forward as if to fire, but runs into a bar that gets inserted between in and the bolt so it never reaches the cartridge. In this condition, the next pull of the trigger will pull the striker back to the firing position and release it. All shots are single action unless it was decocked, when it becomes double for the first one. This was designed as a police requirement stating that the weapon had to be absolutely safe, but quickly usable. This is the same requirement that lead to the HK squeeze cocker.
3. 4 into 2 into 1 magazine. (Difficult to load)