I went to 4.5 from 4.0 back when I lived in upstate SC. Moved to Florida few years ago. I don't notice much of a difference. What I have noticed is that the consistent level of play being higher exists in a major metro area (for me, Charlotte) than it does in the rural types of area that I am in now.
I think it is more mental than anything. If you think a state should be stronger, then it will feel like it is.