I've never been inside a fishing cabin. They are not as well-appointed as the honeymoon cabins. (No deer-antler chandeliers, jacuzzis, or "car wash" showers.) But they are otherwise fully furnished, maintained by Big Cedar, and you still have full access to the resort.
Personally, I'd say stay at Big Cedar just because I like the resort so much. I've never heard of Cooper Creek Resort, so I can't help you much there.
If you feel Big Cedar isn't worth the money, I could recommend Still Waters Resort off Indian Point. It's nice. And it's very convenient to Silver Dollar City.