So I am looking into a upgrading my lens. I was looking stuff up and found some articles about Sigma lenses. I wanted some opinions though. What do you think should I stick with Canon lenses or Could I get fast glass from Sigma?? I have a Quantaray lens that I have got some good pictures with but I have also found stuff online that says Qauntaray is mainly Sigma's leftovers. I was also considering a $700. L lens. Do you think Sigma has anything that is anywhere near L glass??