I recently bought this lens to replace my Olympus 40-150. Compared to my copy of the Olympus this lens appears to be a little sharper at the short & long end. But the difference is nothing major. If it was the other way around i would still love this lens. Build wise this lens is better than the Olympus and feels really nice in your hand. Lens looks expensive, has a metal mount, & came with a nice hood. The zoom ring & manual focusing rings turn very smoothly & it has no zoom creep. The Olympus 40-150 looks & feels cheap compared to this lens. If my primary camera was an E-M5 or an E-M1 with the 5 axis IBIS I would of probably kept the Olympus. Unless I had cash to spare because this lens just looks & feels better. But since the IBIS on my GX7 is good not great, I decided to replace my lens Olympus 40-150 with this lens mainly to get the better performance of the lens OIS. I paid $249 for my new copy, & you can usually buy the Olympus for $149 or less, Is this lens worth about $100 more? Only the user can decide. If your primary body is Panasonic, yes, If you use an E-M1 or an E-M5, I still think so. Because this is a beautiful looking lens & would look great on those bodies. Olympus needs to cosmetically update the 40-150. However If you use an E-M1 or an E-M5 & you are not shallow like me use the Olympus 40-150. it's really good inexpensive lens.