I had this lens on D70 & a D300 and the IQ was excellent with good contrast, i sold the lens to fund a Sigma 24-70mm f2.8 for the extra speed but the IQ was not as good on this as the 18-70mm. I also had a Nikon 16-85mm which had excellent IQ but its not a cheap upgrade and i not sure if the extra cash is justified just for the extra zoom range. I now have a Tamron 17-50mm f2.8 which is sharp and has good IQ for the price but you'll lose a lot of the top end....and the 18-70mm has still probably got better IQ, so if you don't need the extra speed and don't want to spend lots of money on a Nikon 24-70 f2.8 then I'd keep it.