I used to own a Sears/Stevens 311. First gun I ever I picked out and paid for myself. I had to have my mother order it from Sears way back when.
It was a good gun. Good enough for me anyway, but I didn't keep it but a few years before I sold it. It was muzzle heavy...very muzzle heavy, with it's 30" barrels. The barrels on them seem to be thicker and heavier than other doubles.
I used it for squirrel and deer hunting. It probably would not have been a good bird gun. But the guy I sold it to raved about every time I saw him for the rest of his life. He never mentioned any problems. I know he said he used it more for turkey hunting than anything else.
The 311 and the Fox B are the same gun as someone said. The Fox B was just a little nicer, but it had a single non-selective trigger. Personally I prefered the double triggers on the 311 so that tipped the scales to the 311 when the time came. I very seldom wanted to fire the tight barrel first, but with the twin triggers I could do it if I wanted to.
I've been tempted to buy one recently, but only as a nostalga trip. I see a lot of Stevens, but I'd like find a "Sears" gun like the one I used to have.
If I was going to buy either, I'd buy a Stevens, because of the double triggers I mentioned. And I'd only buy one if it was inexpensive enough. I see them both for around $350-450.00. My LGS has several Lefever Nitro's for less.
And JMR40 is right. A pump gun is more practical. But it's not the same.