As Dave mentioned above, the biggest issue on the Mossies is the location of the safety. You will be required to drop your firing grip to access the tang mounted system. This problem is not encountered on safeties designed around the trigger-guard area(Remington, Benelli, Berretta, etc).
Arguments about pistol-griped stocks will continue. On a combat rifle, they allow the user to perform reloads without loosing their firing-grip. As with my AR15s, all mechanisms are accessable with the firing hand on the pistol-grip(trigger, mag-release, safety). Of course, the bolt-release is not, but this is covered by the non-firing-hand after insertion of a fresh magazine.
The Benelli M4 is now being produced for the US Marines. It has the pistol-grip design, BUT it also has an oversized safety located on the trigger-guard behind the trigger area. If a tang mounted system was specified, the use of a conventional stock would have also been chosen, I'm sure.
Unless you plan on carrying the Mossy with the safety off, during employment, you will be greatly slowed when it comes time to fire. Firing controls are designed to be ergonomic. The Mossberg's safety is designed for use with conventional stocks. Just a thought.