Thinking about the Sigma 17-70mm F2.8-4 DC Macro OS HSM for Canon to replace my kit lens for my rebel XT (D350) Will this work and any opinions? I would have went with the Sigma 17-70mm F2.8-4.5 DC Macro minus the HSM but I can't find anyone who has one in stock. Does anyone know if sigma is still making them the older style that is. I have read the reviews on the non hsm one and it looks like a good step up from the kit lens for the price. Any opinions welcome.