MARCH 2016 UPDATE: This lens has not been used since September 2015, because ALL of my images taken at 24mm from a distance are soft/blurry. It has been tested on all 3 of my bodies & a friend's Canon 1Dx - same results!! NOT wanting to send it back to Canon at this time.
I rented this lens the end of October 2006 for 30 days from lensrentals.com & fell in Love with it. I bought it in January 2007 from B&H Photo. It WAS my #1 "go-to" lens. The only Negative was this lens quit on me in October 2011 while I was out shooting(lucky for me I had my 28-135 IS lens with me). When I sent it back to Canon the repair bill was around $325.00 - NOT good, but it's great to have it back & working.