For the price not really bad, but strong CAs and on the last end slightly out of focus. At a 18-135 WR part of the optical error is corrected. Although not much better at the edge. Digital reingezoom in the 135mm Ergebins are equal to the 200mm of Tamron. Rods push very loud and slow. So if it is concerned only with the pure image quality really is not much worse, but the quieter and faster focus with manual intervention and the internal correction give as rash. If the price and that is not bad.
