I bike everyday to work and back. Ponchos suuuuuck to ride in. Theyre constantly getting into your chain or wheel. It's hard to do a shoulder check because you'll get poncho in the eyes. And the wind getting in will make it come off your arms and head. Plus they're uncomfortable with helmets and biking gloves.

Personally, I just use a rain jacket plus accept the fact that I'll get wet sometimes. I already carry a towel in my rear rack for sweat so it's not that big a deal as long as I get to my destination.