Excerpt: Despite being relatively light in weight, it felt robust in the hand and well-balanced on our EOS 60D body. The zoom extended smoothy and during testing, the AF performed quickly thanks to the built-in Ultrasonic Motor (USM), locking onto targets with no signs of hunting.
Canon EF 70-300mm f/4-5.6 USM IS - APS-C Format Review / Retest
21 June 2009
Conclusion: The Canon EF 70-300mm f/4-5.6 USM IS is a very decent performer when used on an APS-C DSLR. It is capable of delivering very good results throughout the range. The peak performance is, of course, in the lower range but the results are still pretty impressive at 300mm.
Canon EF 70-300mm f/4-5.6 USM IS - Review / Test Report
7 June 2007
Conclusion: The performance of the Canon EF 70-300mm f/4-5.6 USM IS came as a total surprise. Unlike its predecessor the lens is capable to produce a very high performance throughout the zoom range without the significant drop in quality at 300mm typical for most consumer grade lenses in this range.