School me on Roof Materials - Have they improved?

Being in California, where it's hot.... the roof probably should be inspected every year and resealed, rather than waiting for leak until it's re-sealed.

The roof sealant commonly used, called Dicor, works good, but it will dry out and get brittle in extreme heat / sun exposure, but usually that takes more than a year or two.

What kind of sealant are you using?