Well - - - after testing the shots that I took on the E-3 last week in my own workspace and printing out samples to verify the quality of the 50-200 SWD lens, today was the day to go purchase it. However I decided to take along my E-510 to try the lens out on before I finalized the purchase.
Mounting the lens to the E-510, I could not believe the feel of the combination in my hand. It appeared a perfect match easily gripped and carried around the throat of the lens. Then when I lifted the camera to take a few test shots in the camera store, the focus snapped into place quickly. Heading outside I extended the zoom and found a far off object to lock on to and then quickly moved in to a close object and was able to find focus very quickly. From my initial playing this evening, I would have to say that the focus ability of the 50-200 SWD on the E-510 is only a bit behind that of the E-3 - - - certainly not enough to discourage the use of this lens on the E-510 by any means.
In my opinion, if you are wanting to benefit from a fast and furious lens like the Olympus 50-200 SWD, you don't require an E-3 to do so. You will get almost as much benefit and pleasure if you have only an E-510. Plus, this combination is almost something that you could walk around with without breaking your wrists.
Probably a little bigger and heavier a lens,
BUT THE FEEL AND LOOK IS A LITTLE REMINISCENT OF MY FAVORITE "OM2s Program" WITH MY 300mm f4 ATTACHED.After I got home this evening, I had Anne hold the 50-200 SWD mounted on the E-510 - outside the back door lit by a floodlight that lights our porch when visitors arrive (both shots taken with my E-3 and 12-60 at 1600 ISO):