CJ,
I have two of them, one on a 22 magnum and the other on a Remington 700 .222.
I am very happy with mine, nice and clear, lifetime warranty. So far so good.
I think the 4 power one is for 22 rimfires according to the literature on them so I don't know how it would hold up on a slug gun. They make a 2-7x32 that they are targeting towards shotguns. Again I don't know for sure if one is any more rugged than the other.