Summary: While this is a somewhat small plastic lens body, the quality is very good for something with this kind of range on a Micro 4/3rds body, and I have no concerns about the durability However, because it's not optically stabilized, it will have reasonably intense light requirements -- restricting usage to higher ISOs and sunny conditions. This would be a good zoo lens, usage on birds may depend on how much shade surrounds them.
Summary: I've had this lens for about two months. I have found the image quality to be excellent -- but, it must be used with a tripod to obtain that quality. Although it is a fairly slow lens in terms of aperture speed, I find that the range relative to effective focal length is about what I need anyway to obtain proper Depth of Field. It is very well made and feels solid. It focuses fast and very accurately.
Summary: I've had this lens for a month or maybe a little longer. My first impression was 'Wow what a light and tiny long zoom lens!' I think so far that size and weight are the biggest pros. I bought it to replace the Zuiko 70-300 which is larger, heavier, half the price and needs an adapter to mount it to m4/3 cameras. Pros: ---Light and small for such a long zoom. Very easy to take along when you might leave a larger/heavier long lens at home. ---Good contrast.
Summary: This lens is great. I bought it to try and take up wildlife photography. Taking pictures of birds in flight with this lens, the e-pl2 autofocus, and a beginner's skill level has been challenging (ok, impossible), but I'm keeping the faith that my skill will improve to the necessary level. For all other purposes, however, the lens has performed stupendously. I just wish it wasn't so dag gum expensive...
Summary: Price is a bit expensive but I love its small size and lightweightness, and I think it works very well. The photos I took are pretty sharp. Auto-focus performance is excellent and range is okay. With the price, the maximum aperture range should have better.