I've had this lens in Etosha National Park in Namibia the last week and I've been really pleased with the performance. The light here is so strong I don't need IBIS or the build in IS in the lens. on my OM-D. I rest the lens barrel on a bean bag across the car door and the photos are excellent at all focal lengths. I did notice a loss in IQ when IBIS is on and wanted to pass that on in case others are having difficulty getting good IQ at full zoom.