Update: Please check out the newer post http://camahoy.com/2014/01/13/finally-tamron-150-600-vs-canon-400-f5-6l/
The weather is so bad this year. No sun, no snow, just grey clouds. Thats why this was shot at ISO 3200. I promise you to make something at ISO 100 or similar, wont make much of a difference.
The Canon lens doesn’t have a UV-filter anymore, from the initial test in my appartment, they looked equally good when UV removed. But outside, the same thing appears again, Tamron looks sharper.

Canon 100% Crop

Tamron 100% Crop
Ive tried to test out the auto focus as well, but there simply aren’t that money birds around this time of the year. But all i can say is that it does hunt sometimes, but so does the Canon. It take a while to figure out how a lens behaves, so i need more time for a verdict.
I promise to update more as soon as ive got something to show. I work crappy hours for me to do day light shooting the next few days. But i will borrow a Canon 70D to show how it looks on a crop sensor for the people rocking the 7D and similar.