Two things: One, I own and use the 55-250. It does produce good images, but if I was going to buy a telephoto lens again, I would go with the 70-200 f4L IS in a heartbeat. IS is EXTREMELY handy especially with the longer lenses. The difference from when I turn it on to when I turn it off is staggering; I don't have the steadiest hands so it gets shaky real fast in the viewfinder. That being said, even without IS the 70-200 f4 is still a stop faster on the long end and has much faster AF and better image quality so I hear.