Summary: Contrary to eBay's auto-title, this lens is for CANON EOS (EF Mount lens), Tested with Canon EOS5q 35mm. The lens mechanically is a push/pull zoom system, love it or hate it, Sigma have done an OK job with this one. The mechanism is a little stiff which can make fine grained adjustments a chore. However this does prevent (in my model at least) the zoom creep found in many push/pull lenses.
Summary: I have absolutely fallen in love with this lens. It's a manual so you can fine tune you shots perfectly. The lens can really get a good shot from a distance. Taken a few distance building shots and WOW - they look great.
Summary: I like this lens I got a great deal on it and it does everything I want/need it to do. It is a cost effective 70-300 mm zoom lens with some basic macro capabilities. only issue I have had with it is it takes a while to wait for auto focus but most of the time I am using manual
Summary: I love this lens. I am using it with my Nikon D40. Very fast auto focus that does not drain battery. A great deal considering the cost of other lenses less than 300mm. I occasionally use with a doubler, auto focus doesn't work with the doubler, but this is a limitation of the doubler due to the f/4-5.6. With the doubler I have taken great pictures of wildlife and the moon.