I love the bullpup design in theory and looks as well as for some functionality. ANd here's the but.
Use of bullpup designs have one shortcoming. Shooting from the right side of the street in urban settings. Spent casings have been seriously injuring soldiers who fire when up against buildings, or firing from right side barricade positions, and on the right side of the street. The casings bounce back with enough force, and close to the face to cause sustantial damage to eyes and flesh. All this includes firing from the prone position as well for some.
In certain armies of the world there are many troops who will not patrol the right sides of the street in urban areas and their commanders agree with this. Other different rifle style troops get the nod.
That is one of the reasons bull pup rifles, though the rage, are not universally accepted by the world's armies.
There are many advantages to a bullpup design, but one has to know it's limitations before jumping on the bandwagon.