Connected to the PEN it focused fast and shoots well at long focal lengths thanks to the PEN integrated image stabilizer sharp images. Moving subjects are to photograph well with the lens, but definitely need exercise. I had especially with the long focal lengths longer practice needs :-(.
Macro shooting makes the lens wonderful and maps them with, I think, special sharpness. For moving subjects I needed some practice again.
The lens could be brighter, so it has from the onset of dusk difficulties to find the focus. But I think that this is simply due to size. At the latest PEN E-P3, the lens focuses the way particularly fast, though I at my E-PL1 never had the feeling that would focusing it slowly.
All in all I rate the lens but with 5 stars. It's really fun to take pictures with it and the results are really great.