It’s lightweight and can be controlled with one hand.
Collapsed, it can be comfortably fired by a 5 foot tall shooter.
The strong hand grip is right around the boreline, so it’s easy to point accurately.
It’s about the same length as MP5K PDW submachine gun, while much more powerful, accurate and slightly lighter. It’s also completely ambidextrous. Recoil impulse is similar to the 9mm MP5.
A user who might prefer a pistol grip configuration can swap furniture in a minute, it’s all cross compatible. The main down sides are also functions of the design:
- Checking of the chamber status is slower than on a conventional rifle.
- Downward ejection can be a problem if shooting sitting in shorts or prone with short sleeves. A clip-on brass catcher fixes that.
The pluses are more numerous:
- Empty casings don’t end up in the faces of people next to the shooter, or bounce off barricade or wall into the shooter’s face or arms.
- Five pounds is easier to carry or hold up than six to seven pounds typical of competing designs. You can have an RDB-S with a red dot, a sound suppressor and a full magazine for what a bare-bones Sig 556 weighs.
- Felt recoil is more like 22WMR than 5.56.
- Gas system can be tuned to work with any load, and also for sound suppressors. Minimal gas blowback.
- Very slim form, especially with a flush-fitting 10-round magazine.
- 16.1″ barrel compared to 8″ of a similar length AR15.
- Variable length of pull with adjustable stock, uncommon for bullpups.
- Folding iron sights of good quality.
- Very high grip keeps the rifle from rolling even if a relatively heavy optic is mounted. Also keeps muzzle from flipping up on firing.
- Simple, easy to maintain design. If you look at the parts diagram in the instruction manual, you will see that most of the parts by numbers are screws and nuts, while the actual mechanism is very simple.