I live in Oklahoma City and have attended the Affair of the Heart many times over the years and enjoyed it. It is a 3-day affair here, and you can go multiple times.
It has changed through the years, though, in my opinion. It really used to be a marketplace for lots of handmade items. You could find some really unique things.
The last time I went was a couple of years ago, and I was disappointed. There are more and more "storefront" type booths from all over the country. It has gotten very commercial, and the handmade things are in the minority.
I remember long lines at a booth that manufactured velour bunny rabbits. They were cute, but machine made, with monogrammed ears. You had to place an order and they sent them to you.
Bugga in OK
"Be kind whenever possible. It is always possible." Dalai Lama