Newsflash...Don backs Canon Lenses
Boys....you heard it here first. It would seem that Don has turned over a new leaf and will no longer recommend Tamron Lenses over Canon Lenses, when used on a Canon body.
A Quote taken from the Don on the Sony Forum
"Let me tell you a little teeny tiny secret ... SONY is a major shareholder in the TAMRON lens corporation ... and that TAMRON has made several previously labeled/packaged "Minolta"-lenses and "SONY"-lenses.
SO ... bearing that in mind, which company would have a more "in-depth" relationship with the aforementioned SONY?
TAMRON ... it just works better ... on a SONY. (You can also ask "Sparkie" how well Quantaray/SIGMA lenses hold up under the riggers of being mounted on a SONY body.) A lot of users prefer the TAMRON 17-50. The alternative isn't the SIGMA, but the SONY CZ 16-80mm f/3.5-4.5 (which is almost double the cost).
Hope this helps in your decision."
From this, I can only assume the same logic can be applied to Canon :)
Calling Don....Calling Don :p