You should know, though, that you do come off as a very strong Nikon fan, given that you regularly seem to try to insinuate that Canon technology is inferior to Nikon technology...for pretty much every technology these kinds of cameras have. I haven't ever really seen you argue that anything Canon does is better. I've seen you make one-liner statements kind of to that effect, but when it comes right down to it...you seem to think Nikon is superior in every respect. That perfectly fine, everyone has and is entitled to their own opinions and preferences...but, it does come off a certain way. It comes off to me the same way I must come off to you, only the brands are switched.
I see what you're saying, but here's why it's like this:
I come in and specifically counter some false generalization that Nikon X is worse than Canon X (like the D800 AF is inferior to the 5D3 AF). That requires pages and texts of explanation, b/c no one here wants to accept it. You won't even try the Nikon out, resorting to some basic tests with your Canon that may or may not correlate with the real-world shooting scenarios where I've tried both systems. So I try to explain, post videos, then eventually give up.
OTOH, I only provide 'one-liners' when it comes to a superior Canon tech (dual cross-type points providing more potential detail to focus on, wider base-lines providing more accuracy, potentially anyway, the wireless flash system, etc.) b/c no one here is making some false generalization about those being poor or worse than Nikon. And, naturally, since this is Canonrumors, where Canon people reside who don't want to think they made the wrong decision (that included me for many, many years - and if you must know, I still have my 5D3 and will continue to have it until I've convinced myself from empirical data that Nikon is not noticeably worse in AF precision with 24/35/85 primes - though Roger Cicala's initial data suggest the systems are comparable). For now, though, the D810 has solved many of the problems people have asked solutions for here, while introducing little to no negatives (yet).
So in the end it boils down to this: I don't need pages of text to convince you that Canon is better in one respect or the other. You'll gladly digest it in one line, one phrase even. Something Nikon is better at? Not a chance, without writing a novel & presenting irrefutable data. Which, obviously, I can't do. That's fine. But I am glad I refuted the general statement that '5D3 AF is clearly superior to D800 AF', b/c maybe that'll actually make someone try the systems out before being misled by a generalization that may or may not be applicable to him or her.
Make sense now?
I think your misreading things. Misinterpreting them.
I also HAVE tried the D800 AF system in stores. You made the assertion that's all I needed to do to know how much better it is. Sorry, but, the differences have never seemed that obvious to me. I also used my 5D III in a very specific test scenario that you described, rather explicitly, as THE case where I would, without any question in my mind, notice that my 5D III "was basically useless at." Focusing with a short lens on a subject moving rapidly and erratically around. That isn't some "general real-world shooting scenarios", that is a very, very highly specific use case that you ultimately narrowed your argument down to the last time we had this discussion. You keep changing your argument. One minute the Nikon 3D AF system is just better, period. Then it's on par with the 1D X iTR system. Then it's only this one specific use case where you can really see the difference. Then it's back to being real-world shooting scenarios (which I can only assume means things like wedding photography, sports photography, etc....because all of those are "real world".)
I dunno. I'm not working from an empty slate here. I've had a D800 in my hands on many occasions. Sometimes out in my regular birding haunts, albeit with much shorter lenses than I usually shoot with. I didn't like how it fit my hands, and I honestly did not notice any glaring differences in the AF systems. I'm happy to admit there may be some differences in specific niche use cases, as the one you alluded to the last time we debated AF systems. This isn't some stubborn Canon loyalty here. My brand loyalties are pretty much gone...I'm willing to try anything now, buy anything, once I figure out what will serve my needs. I'm quite interested in the Samsung NX1, even! (I doubt any Canon photographer on these forums would be willing to say that.) I simply don't believe the hype here that the Nikon AF system is so vastly superior to Canon's (the one in the 5D III) that the differences are so obvious I'd think my Canon AF system was useless (oh, sorry, gotta make sure I'm quoting EXACTLY the right words here: "ultimately so unreliable as to be practically useless"...hmm, yeah, same difference: useless).
I honestly don't care how much widespread personal experience you have with these systems. What I am saying, and I'm trying to be very, very specific here, is: The Canon AF system in the 5D III is NOT "ultimately so unreliable as to be practically useless" for the use case you described the last time we had this debate. The use case of photographing an erratically moving subject close up (and therefor with a thin DOF) with short lenses. I've tried it. It's not 100% perfect, but if it works well enough with my EF 50mm f/1.4, it'll work well enough with pretty much any lens I throw on there. I also have experience tracking erratic birds in flight as they fly towards me when using the 600mm lens. I've never had any problems with that. Is it better than a Nikon system? No, not saying that. That was never my point. Not what I'm interested in. Is it "ultimately so unreliable as to be practically useless"? HELL NO! You have repeatedly made the claim that Canon's AF system is useless in certain specific circumstances...I DISPUTE THAT. Very specifically. I'm not here to say Canon's AF system is superior in every respect. I'm only here to say that your WRONG that Canon's system is useless for certain things. I've tried those things. My 5D III performed at a level WELL above "practically useless", well above "mediocre". It performed, with my worst lens for AF, rather admirably. It seems to perform just fine with my 16-35 L. I don't know if it's better or worse than a Nikon, but I really don't care. What I do know and care about is that it doesn't plain and simply suck at that kind of AF use case.
Do you understand, now? Your really reading a lot of things into what I'm writing that I'm plain and simply not saying. I really don't care so much if the Nikon 3D AF system is a little bit better in some scenarios, or a lot better in a couple specific scenarios. The same thing could be said for Canon's AF system (either with the iFCL meter or with iTR), and I do believe that when it comes to tracking sports activities, the reviews generally point to the Canon iTR system as being the superior system. Would the 1D X perform as well or better than the D800 in your specific use case? I dunno, but if my 5D III performs as well as it does, then I suspect the 1D X with iTR would perform better. That's different than on the IQ front. On the IQ front, there is no contest. Canon wins, hands down....the place of dead last. It doesn't even matter if were talking about Exmor anymore. Even the rather lowly D5300 sensor from Toshiba is trouncing Canon APS-C sensors, and has more overall dynamic range than any Canon sensor. I'm willing to bet the Samsung NX1 sensor is still superior to Canon sensors.
I'm not here to say Canon is better at everything. However, there are specific things I do believe. Canon has NAILED ergonomics as far as I am concerned, and Nikon cameras simply don't fit my hands. Canon's lens lineup offers a greater diversity of types and offerings, and overall (not in totality) the lenses offer unparalleled quality. That doesn't necessarily mean they outresolve everything...not every lens is designed for raw resolving power. However, for what most of Canon's lenses are designed for, I think they nailed it. Extremely low flare for most of the new lenses that use SWC, ultra fast AF when paired with the 61pt AF system, very high resolving power in most cases (some exceptions, although most of the time it's by design), unparalleled quality in every respect for their white telephoto and supertelephoto lenses with the one exception being the 800mm f/5.6 (I think Nikon's outdoes it, however Nikon's design is nearly brand new and uses the same flourite elements as the rest of Canon's supertele lineup.)
I think Canon cameras are lacking certain useful features. WiFi and GPS in every body would certainly be useful. I hate spending time to geocode my images in post. Resolution is lagging behind the rest of the industry now, and I could definitely use higher sensor resolution for some of my photography. They don't seem to hear the call for Dual CF or Dual SD. I get their reasoning for both, but it doing both seems to annoy more users than find it useful (including me.) There are plenty of things Canon sucks at. I know that. I don't think AF is one of them.