It does have some disadvantages, sure. It has range limitations (but not that much, it has fantastic range for a shotgun), the reload is a bit slow(although, again it is one of the best for shotguns. Only the SLY might be a tad faster), and enemies can pick it up and use it's overpowered-ness against you (this is also true of other high level guns though, and hardly balances things out when you get it at every spawn and enemies have to look for it and leave themselves vulnerable when they stop to grab it).
If they had made it semi-automatic only, fire rate of a pistol, it would still be great but just not so cheap. That's my opinion.