I have been researching safes a lot lately. I checked out Superior in person and am leaning toward a Master 50. Overall it is a nicely built safe with a lot of features. Someone will be along to tell you if you dont have 4ga walls, its worthless. I have quickly realized in my research that unless you step up to true safes TL15 - TL30, etc. anything can be defeated. Security is about layers. In my opinion the Master Series offers a lot a a great price point.
The negative that I have, at least for the 50s, is the self strength leaves something to be desired. I will likely be adding additional supports to the full span shelves.