Ha, so I have 4 of the guns on your list, 5 if you count the Swiss CQB.
The XCR micro in 7.62 is the loudest gun I have ever fired, its louder than my CSA 7.5" due to the muzzle brake on it, and can hold 10 rounds of 7.62x39!
The FAMAE leaves some things to be desired, in my opinion. Swiss is a great gun but likely in the 3k range, and the stock is not adjustable for length of pull, but it still side folds.
Skorpion is fun too but is not really the same class of gun as the rest!