I did some research on this for anyone else wondering. Vinyl pads are the "skinned" variety, and paintable.. very similar to the original pad. Urethane pads are not as easy to paint, and are a solid construction, not a vinyl skin over padding. Sounds like they might be durable, but are very flexible, difficult to get looking good and straight, and take a lot of work cleaning urethane out of mounting points, etc.