Hi every body,
This is my first post so please be gentle (hehe)
Been using a Canon 50mm Macro on a 1000D ( Enjoy the details of flowers and maybe some bugs) now i want to upgrade to the 100mm, beside price is there much of a differnece between the IS L and the standard 100mm lens most of my shots are hand held, so Im sorta leaning towards the IS. Also I keep looking at the Sigma 150mm Macro, there is a new 150mm on Sigmas site but no price. What are your thoughts on the 3.

Thanks for your time, and apologies if this question has been asked before.