The Saturday night required stay applies to NW also. I go with NW and UA for the ff programs. NW has better prices for bought tickets, so I can take more status miles trips for the cost. UA requires 25,000 ff miles for a domestic ticket and no Saturday night (I'm glad everyone made a ruckus earlier this year). The extra 5,000 miles is worth it since I work almost ALL Saturdays! My airport of choice (EUG, Oregon) is possible on award travel on both these airlines. CO doesn't have award travel to or from Eugene.
I guess everyone has their own system for rating the ff programs, and living in a small town tends to individualize it.