« on: February 16, 2015, 12:52:53 PM »
Here is my experience: when use my 7D2 with my Tamron 150-600mm, my keeper rate is not high and AF seem not consistent. When use my 7D2 with my EF 400mm F5.6L, my keeper rate is way higher and AF is fast and consistent. So my conclusion is that my Tamron 150-600mm had some issue with my 7D2.
By the way, my Tamron 150-600mm had a live view AF issue with my 7D2 (no such issue when I use with 60D and 6D), but not sure does this issue affect the normal AF operation, but will going to do a 1 to 1 exchange tomorrow... after that I'll sell the Tamron and join the EF 100-400mm II club...
That's one of the reasons I've shied away from non-Canon lenses, since they would have to be reverse engineered. I know that some Sigma lenses can be updated after the fact with a docking station. Maybe Tamron has a firmware update that would take care of the problem.