I've decided to get a macro lens that will double as a portrait lens, though I don't take many portraits. These two fit the bill, though I was previously considering a 100. The canon is 200 bucks cheaper and the only noticable difference is the f-stop. I'm not sure if that justifies the price difference. Does anyone have these lens, if so, i'd love to hear your thoughts. I have held the canon and it is a very light lens, but the reviews say it is sharp. Thanks for the help!