I have a Stevens 311. It’s a good solid gun, identical to the Fox B except the Fox has some pressed checkering. IMO the 16ga is the sweet spot in that platform. The 20 and 12 are both too heavy and clunky for their size.
The Fox Sterlingworth and LC Smith Field Grade are a step up, but probably not any “better” from a practical point of view.
Pretty much all American doubles are designed for general hunting with an emphasis on waterfowl… so they tend to have a lot of drop in the stock, and be rather heavily built compared to the light English guns that are designed for shooting driven birds.