Summary: I have just about every Olympus micro four thirds lens and this is the one that I am most impressed with. I find the pictures to be sharper and colors better than with the 40 - 150mm and 14 - 42ez, which are both good lenses. It has a nice weight and feels very solid. It seems to be about the same size as the 40 - 150. The zoom is very smooth, no lens creep, quiet and blazing fast autofocus as all the Olympus lenses do. It is a great walk around lens and good for sports.
Summary: I have to admit that this review should have been written couple years ago when I have purchased this lens. I have put it on my Olympus EPL-1 and it stays there all the time, unless I use my fish eye lens. I have 14-42mm kit zoom and 40-150mm zoom, but they do not give any advantage in image quality over the subject of this review. This is not a fast lens, but there is no fast super zoom in existence anyway.
Summary: For what it is, I find it to be pleasantly sharp all around - wide & tele, wide open & stopped down. It captures great images, and this plus the fine Olympus 60mm macro are all I need for an excellent day in the backcountry. It's nice not having to swap lenses from wide to tele, and unless you're a super OCD pixel peeper or making poster sized enlargements, this lens gets it done.
Summary: Nice lens. I use it on Blackmagic Pocket Cinema camera and autofocus feature does work. However, 14mm is not wide enough on the Pocket Cinema camera to be much use when filming people indoors – unless you are going for strictly closeup shots. For telephoto shots, the lens is great!
Excerpt: I have only had the lens a couple of weeks and use it with my Olympus OM-D-M5. So far it has given me very sharp images. I especially like it's compact and light feel. The Zoom (28-300mm in 35mm equivalent) covers 95% of the shots I take, so I really like never having to change a lens and then miss the shot.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Lightweight