Summary: It is a great lens but not too good for action shots! The clarity of it wasn't as good as I was hoping for it to be for action shot, but for everything else it was very nice. I really like the hood that came with it to help minimize the lighting. I would recommend buying Canon brand for this type of lens on action photography.
Excerpt: Had an aging, malfunctioning Tamron 70-300mm lens that needed replacing. This is my first Sigma lens and thought I would give it a try. So far, it is functioning perfectly on my Canon EOS T1i.
Sigma 70-300mm f/4-5.6 DG APO Macro Motorized Telephoto Zoom Lens for Nikon
S. M. Miller, Amazon
27 September 2014
Summary: I purchased this lens for my D3200. Firstly, I will start off by saying I am an amateur photographer. I have had a DSLR for 4 months now but I am a very fast learner. This is my 3rd lens to my arsenal. Others being my 18-55 VR Kit lens, and my beautiful Nikkor "nifty fifty" 1.8 D lens. I bought this lens for $150 and I will say i rated it 5 stars because its worth every penny. People on these reviews rating this lens poorly because of this and that are picky. Too picky.
Good lens for the money, but some build quality issues
James Pittenger, Amazon
23 September 2014
Summary: EDIT: I will leave my original review below. I contacted Sigma about the problems I was experiencing with the lens. They advised me to fill out an online service form and send in the lens to their service department. Since the lens was under warranty they replaced it with a new lens. They service was incredibly fast as well. I filled out their contact form on their website and received an email response within an hour.