Have the same setup. Works as any other lens. Not sure what you mean.

The 70-300 is a great lens but is a little soft on the high zoom end. It is also a f4.0-5.6, which limits low light situations. If you have the money, the high grade Olympus lenses are better, sharp edge to edge at all f stops and zoom ranges. You can find some on Amazon. Just get the "very good " condition from a US dealer. I think the 12-60mm is cheaper than the 50-200mm. The SWD auto focus mechanism is designed to work with the E-3. It is fast and quiet. I think I would hold off getting the 70-300 and save money to get the 50-200 and if you can find on the Olympus EC14 (1.4x teleconverter) get that. This will get you to 283mm at f4-4.9. with much better sharpness and resolution. You will be able to crop this even more. Even at 200mm you can crop and still get a better image that the 70-300.

Carleton.
Just make sure you get Olympus DSLR 4/3 lenses and not micro 4/3. The kit lenses, 14-42mm, 40-150mm and the 70-300mm are really good and cheap. The 12-60mm and 50-200mm SWD lenses are more expensive but are much better.