The Head over Heels series has larger flowers. They are perennial and can be trimmed to the ground after each season.
Growing up my grandmother has lots of Rose of Sharon as these were called back then. They were heavy in the seed category therefore spreading all over the yard. These new refined Rose of Sharon do not spread in the invasive way that old varieties did. Plus, the flowers are much prettier, longer lasting, and are re-blooming. I'm now using these plants in some of my landscapes for their summer blooms. Very nice!