Still I prefer the H&K MP5. Preferably in the SD configuration.
Had an original Interdynamics KG-9 once upon a time. It was good in that it fired from the open bolt position. Ran a lot cooler than nearly all of the current "sub-gun" offerings. As well as being readily converted into a "bullet hose".
Best part was it was around 400 bucks. Wish I had never gotten rid of it.
If this is your thing though. This looks to be quite capable, if rather pricey