`Unless there are other side issues like the 70-300 IS having sharpness problems when tilted vertically, or some motor or other problems that might come out later, vignetting, etc., based on the MTF charts alone, the 55-250 IS is an excellent lens that will surprise many. In fact, if the MTF charts aren`t lying, many will find that this lens will likely be very sharp at 55-135 wide open that one will find it hard to believe that a consumer grade lens took the shot. Canon may not have given us a ef-s 50-135 f2.8 IS, but if only if sharpness is as the basis alone, we might start having people comparing it with the 70-200 f4L IS instead of the 70-300 IS`
