At the end of the day, it's your gun and you can do what you want with it, but I look at this and say I would never put this in a catalog for player purchase.
Why? It's perfect.
Every gun in the books is balanced with bonuses and limitations. Want that higher fire power? Sure, but it's SS, and low ammo. This gun is pure win, and has no limitations, since it can be further modified with either internal or external smartlinks. There is not a reason I can think of to not carry this weapon, assuming you houserule the High-Caliber ammo to be below 20F, other than I might want to use a silencer... and even then, I might look into getting a mage friend to cast Silence on me, because it's just that awesome.
Just pointing that out.