I am reading (most of) these posts with interest. It may be that someone else has touched on this, since the number of posts is fairly high, but I´ll give it a go.
I am not an expert on all the technical aspects of the bodies we are discussing. I am first and foremost a photographer, trying to get the best images with what I have. Currently I use 1DX and 5DIII as my main bodies, but I also have 1DIV and 7D. And I am looking forward to the 7DII. But my main concern is AF and not IQ. For everything that stands still, I prefer to use FF bodies (a few thousand reasons have been posted before this one). I have lots of high quality glass to get the framing right, so my interest for a cropped camera is only for long reach.
As I see it, the real benefit of a 1.6x sensor, besides cheaper lenses, is in combination with a 400/500/600mm tele, possibly combined with extenders. The AF system will work on a closer framed image and thus give me a better opportunity to secure focus on the specific part I want in focus. When I crop an image from a FF, it´s more of a gamble. But currently, the AF systems on both the 1DX and the 5DIII are so much better than the current 7D, that you don´t really have an advantage with a cropped sensor. So at the moment my 7D stays in the bag (actually at home). But with the 7DII, that may all change.
So, I cross my fingers and hope for a best possible AF system and good high-ISO performance (rather than very high resolution) on the 7DII. I´d be interested if some of you more technically competent could comment on this.
Man you are reading my mind. Exactly same thing here. IQ at this point is last on my list. With AF being on top.
As others though am hoping for better IQ too?
I've made the same argument in the past. To me, both AF as well as frame rate come before sensor IQ. I don't see any real drawbacks to the 7D IQ as it is, though. I think my previous example posted a few responses up demonstrates that the 7D can extract more than enough detail to overcome any drawbacks such as higher noise (especially, as Eldar stated, when paired with a 400/500/600 and a TC).
I would go so far to state that one of the primary reasons the 1D X can do as well as the 7D is because of its AF system. The 7D's 19pt AF, while good, definitely has it's drawbacks. It's margin of error is rather large, and any time it decides to confirm focus, its really hit or miss...you might actually be missfocused enough that the shot (or even a whole sequence of shots) are a bust.
I think my top two biggest wants for the 7D II are 61pt AF and 10fps. Give me those, even with a lower noise 18mp APS-C sensor, and I'll be happy.