A good zoom in a slow package
This is in my opinion a quite contradictory zoom.
In many ways a high quality piece of equipment capable of truly excellent results, but expensive and slow.
The Aperture 6.7 at maximum zoom 600 mm(equiv) means that it requires A LOT of light. Paired with the Olympus bodies, which are not the best high ISO performers it can be quite limited since even an ordinary overcast day limits its use significantly even if the light is good enough for most other lenses.
Having said that the lens is nothing but extraordinary and tack sharp in good light, which in this case means sunlight . But then it really excells on the other hand, producing wonderful images.
Myself I use it not only for long distances to the subject, but also to compress pictures on short distances or for candid street photography. Its discrete look and size makes it perfect when one needs to get close without being intimidating.
Even though being the biggest Olympus m43 zoom, its incredibly small for a 600 mm zoom.
As long as one is aware of its limitations being slow and expensive I can highly recommend it for the sharpness, contrast, build quality and excellent handling.
If it would have been just one step faster I would not have hesitated to give it 5 stars.