HI All I have the Sigma 70-200mm Macro and the 70-300mm (rechipped) you can usually pick them up quite cheap on ebay, and I have heard good reports about TAMRON as well for the Canons (EF/EF-S fittings) I use these lenses regularly and I find the optics great pin sharp and wonderful....but as with anything the quality is not upto Canon standards, and you seem to lose quite a lot of light, although that could just be my eyesight. (IF YOU CHECK MY GALLERIES MOST OF THE PICS HAVE BEEN TAKEN WITH BOTH SIGMA'S). But still acceptable and worth working with them although you do have to put some more effort into to what you want to achieve. They dont focus too great on Auto, but on Manual they are spot on, but heres the but, as with any macro lens 1) dont get too close to the subject 2) remember to compensate for light 3) Use a tripod 4) USe a remote switch 5) Watch for DEPTH OF FIELD 6) Invest in a Macro Ring Flash (if you can) 7) Get a light meter 8) Experiment - Play and get to know your equipment. Just go out and have fun, theres lots to do.