I havn't used one myself, but I did do extensive research on the net to find out it's qualities.
The lens it allways gets compaired to is the Canon 100-400L IS, and it seems it get's very close to it in most areas except one, focusing speed.
Due to a lack of HSM (why?
) the Sigma 80-400 is slow to focus, so if you intend to shoot things that move pretty quickly you might end up missing a few shots, but the only way to know if this will be an issue for
you is to try and get a quick play with one before you buy. I'd really advise phoning round camera shops in your area to see if anyone has one.