Talley wrote in post #16798289
I still don't see what people talk about focus speed and accuracy.
Mine is just as solid as any Canon I've had. Never misses even in the lowest of light.
Talley, my experience is based on 5 copies of the lens. Your experienced is based on one copy. If it indeed does that for you, thats great. Online/youtube reviews all reiterate that the focus speed of the lens is certainly not up to par with the canon 24-70 II which I own, as well as many other canon fast usm lenses (24-105, 70-200 etc). If for your use, you find the focus speed adequate then thats great. However, when it comes to focus speed, its a fact, and not copy to copy variation issue. Now for focus accuracy, there certainly can be more copy variation (though I doubt it, since I have gone through 5 copies). I further question all your assertions, since I know for a fact, the focus speed of this lens is a fair bit slower than the 24-70II, and slower than 24-105, and this is corroborated by other side by side tests.
I am glad you have a good copy that is working well for you. I find it important however to provide balanced, accurate information, and I strive to do so.
I still maintain, that there is nothing to complain about in terms of optical quality of a properly centered copy of this lens, when its in focus. its very good in center, slightly weaker at 70, but still very good, and excellent stopped down, and very good to excellent to corners at all focal lengths.