Canon 28-135 IS f3.5-5.6 - Any good??
 

I've been offered a Canon 28-135mm IS USM lens in exchange for my Sigma 18-50mm f2.8 EX DG.

I'm in the process of changing my 20D to a 5D MK1 and the Sigma is APS-C so it needs to change too. This isn't the lens I was thinking of but it has kinda fallen into my lap so I wanted to see if any of you good peeps have any experience of this glass...

Fire away!