If you only use auto-focus, it works perfectly and the lens is super sharp. However, the manual focus ring does not turn. I called Canon and the guy I talked to estimated $300 - $400 repair, bringing my price up to usual used prices online.
So grab an auto-focus bargain or send it away for repair.
$300 obo
** Also selling a Canon 300mm f2.8L lens professionally converted from FD to EF mount. Very nice condition with very few barrel marks. Glass very good. The manual aperture is great and is de-clicked for smooth video operation if required. Online auction prices for FD version range from CDN $600 for beaters to $2500 for excellent. This was professionally converted to EF mount to use with newer cameras.
$900 obo
Selling because I'll be switching to Sony.
Thanks for checking these out.