Getting an outlet to grip better..

I'm sure it's just a one-off manufacturing defect, as the outlet (Maestro) is well respected and well reviewed.  The bottom plug actually grips reasonably well, but the top is very loose.   

The Furutech looks very nice.  May give that a try after I check out some reviews/discussion of it.  Will check into the Edison as well.  

Thanks for the suggestions, everyone!
Scott

Porter outlets from member albertporter for about $50 might be enough. At least I would try them before spending $200 or so on Furutech and others.

I just purchased Shunyata Research's SR-Z1 AC Outlet and installed it yesterday. Well made, very tight grip, reasonably priced (I paid $70). 

Is it the plug that is loose or is the receptacle/box or box/wall that is loose?

It's the plug.  The entire outlet is secure in the wall.