No personaly experiance with one. The look odd to me but, it would be your rifle not mine.
The one thing I dislike about the design is the bullpup config. I am not to keen on having my face pressed up on the action of a gun. If something happen it happens in the action / chamber area of the firearm in the case of a bullpup design is it right on your face. So a Kaboom could cause some serious damage to your face.