Your Ohio climate doesn't have extremes of either hot or cold. Surely the Amsoil -30 would do the job even running hard on a hot day. At least in the winter I would use the recommended 5W-. I think the manufacturers are looking at being able to have better start up protection with the better quality 5W's available now. Unless you are doing a lot of short trip stuff, the XW isn't going to affect mileage that much. If you driving mix includes very many short trips, I would definitely stick to the 5W- all year.
I ran 5W-30 Pennzoil dino in my 92 Grand Am HO Quad 4 on 3 month OCI. After 11 years, and 180K, I had good oil pressure and no engine noise. Its driving pattern tended to be lots of short trips around town, with 1000 mile weekends now and then. Much of my driving is on 2 lane roads where I made good use of the 5 speed. My son was caught doing 55 a few hundred feet after a right on red. The cop spoke sharply to his mother and let him go.