Mike ...
No I don't have rain barrels. I live in a county-of-origin for water in California. Historically, we get an average of about 35 inches of rain during the rainy season. I never have any run off and I want the water to go down to the deep layers of the soil. It makes the water I apply to the surface of the garden during the dry months more efficient.
In my case, rain barrels would be a detriment rather than a benefit.
Smiles,
Lyn