Im considering purchasing the Canon EF 70-200mm f/2.8L IS USM within the next couple of weeks, but before doing so I wanted to get input from others. Has anyone purchased the lens and later regretted it or wished they had purchased another lens instead. From what I have read, besides price, there seems to be no cons for the lens. It appears to be excellent for sports (inside and out), medium distance wildlife, along with portraits at 100mm and 200m. Any comments on the this lens or the non-IS version is appreciated.