« on: November 07, 2014, 12:50:21 PM »
I use the Tamron 150-600mm as a very decent lens for portability and the 300/2.8 + TCs more generally for best performance. A decent 600 will outperform a very good 400 for small subjects far away, but I would sacrifice the extra length of the Tamron for the much better portability of the 100-400 (and probably pair it with a 7D II) if it is better than the Mk 1. So. if it is good, I'll sell the Tammy and get the new 100-400. I wasn't one of the few lucky ones to have a sharp copy of the 100-400.
I just today sold my 100-400, after having the Tamron 150-600 for several months and comparing the two. I have no doubt that the new 100-400 will probably focus faster than the Tammy does, and it is likely to be sharper at pixel-peeping magnification. I, for one, am willing to sacrifice a bit of AF speed and wide-open sharpness I can only see at 100% (when I can see it at all) for having 600mm native focal length, especially when the new 100-400 will certainly cost more than twice as much as I paid for the Tamron. After having used the 100-400 for years, and the Tamron for months, I value the reach over the other considerations for what I do (many small subjects, far away).
I suspect that when the Sigma 150-600 Sport shows up, it could rival the new 100-400 in most, if not all, criteria. The question will be whether the extra weight of that lens is compensated for by the additional length and cost savings.
But, I am sure that the 100-400 II will indeed be a very good lens. If it butters your bread, I am happy for you.
Agree on what you said. I imagine that the preference of the 3rd party 150-600s vs. the 1st party 100-400 II will be similar to that of comparing the Canon 24-105 to the various Canon 24-70s: some folks will prioritize sharpness and others will prioritize reach. Get what makes you happy.