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I use a 20" RPS Studio BeautiDish with a 580EX all the time; it works great. (BDs are usually used close to the subject, so power isn't an issue.)
The BeautiDish, though, is designed to work with Speedlites, and has both opaque silver and translucent white deflectors that are curved to reflect the direct flash from a Speedlite back and out into the dish.
A beauty dish that is designed for bare-bulb strobes will probably have a flat deflector that will reflect most of the Speedlite's beam straight back, so you may want to rig something like a convex mirror to the back of the deflector plate to more-efficiently spread the beam of the Speedlite. (You can get small, adhesive-backed convex mirrors at most auto parts stores for a few bucks.)
Here's a photo of the 20" BeautiDish that shows the curved deflector: