I recently got a Nex-6, and I have some interesting observations. I've seen some negativity (mostly reading DPR) about the PDAF, but I'm finding it pretty responsive, even with the kit lens (16-50PZ, in the case of the Nex-6). In low light, it can still take up to a second to give the green confirmation, but it does feel much snappier in most use than my Nex-5; I'm plesantly surprised. But recently on DPR, someone mentioned getting good results not even bothering to half-press and wait for focus confirmation. In a couple of dimly lit rooms, I tried focusing on different objects and punching the shutter, and mostly things were in focus! Very fast. This makes me wonder if the PDAF works first to get the lens "close", and then it uses CDAF to fine-tune the results. But if the PDAF result is close enough, that may be good enough. Well, this is just conjecture, but maybe someone with more experience (such as David, hint, hint) could figure out what is going on. I imagine that the 5R must be similar.
So far, I've used the camera in various indoor events with not-great-lighting, as indoor events tend to be, and I'm pleased with the results. AF seemed to be the last thing most of us would miss about not lugging around a DSLR, and that advantage seems mostly gone. I guess the DSLR might still be better with huge tele lenses, but I'm much happier with a Nex-6 than a new DSLR/SLT camera.
The naysayers on DPR are still going on about "slow AF", but even the Nex-5 was only slow in direct comparison with a DSLR, and not all the time. (At least compared to my old A100, they were usually the same, as I recall, with the Nex-5 only sometimes needing more time to hunt.)
I think the big open question is "object tracking" and movement. I'm not sure how to best test this; it's not high on my list of requirements, which may be why I've been pretty much OK with the Nex-5. The Nex-6 has an "object tracking" feature in the menu but I have no idea how it works! It seems to be a one-shot deal. I think the more typical tough case is movement towards you, while rapidly taking photos. For movement, I just have to decide which I prefer -- AF-S or AF-C. You would think AF-C would be better, but I had cases where it would focus in the middle where there was background rather than my subjects which were to either side; it seemed effective when the subjects were more in the center, I think, as I only had a few photos which exhibited this mis-focus.
Overall, I'm pleased with the new camera. I'm still not used to the EVF, but I hope to find that useful one day.
High-ISO is probably a bit better, which is always useful. I look forward to once again being able to use a BIG flash (have to get the Minolta-shoe adapter). The focusing is very responsive, and I suspect it's the PDAF, which I was hoping would be an advantage.
The 16-50PZ lens, I'm still reserving judgement. In general, I'd say it's pretty good in the middle focal lengths from 20mm on up. At wide angles, it suffers from corner smearing and curious bokeh, but the center still seems sharp; I'd rather use the 16mm prime. At the 50mm end, I'm not sure it's so bad as people like to indicate. Haven't done any back-to-back comparisons, but photos at 50mm look nice and sharp. Not sure what people are complaining about. It does have a "slow" aperture, though. No hood. Well, you have to live with some compromises in order to have a collapsible zoom. It's really compact for what it is.