The 5D3 and 6D sensors have lower pixel count and poorer low ISO dynamic range compared to that on D800 and D600 respectively. So, there is no technical advantage whatsoever in Canon cameras
How is that people continually fail to understand that a "camera" is not a metal/plastic box with a sensor inside, any more than a car is a metal/plastic box with an engine inside? I was car shopping recently, pretty much every vehicle I was looking at, different body styles from 5 different manufacturers, all had a 3.5L 6-cyl engine. Does that mean there's no real difference between them?
Yes, the sensor is important. No, Canon doesn't make the best sensors from an IQ standpoint. But until consumers start buying bare silicon sensors to take pictures, what matters is camera performance, not only sensor performance.
so if canon tomorrow released the 5Dmk4, which was 2MP, had 1 stop of dynamic range shot in black and white and maxed out at ISO 100, but was twice as good in every other way as the current camera, you'd buy it?
NONSENSE.
It is an imaging device at the end of the day, and it needs to perform as an imaging device. sure it is not the only metric, but the end result is what you get, what you charge for, and what speaks of your work. You'll never look at a picture and admire it based on camera ergonomics, or wifi support, or how many cross points it has. Pixels do the talking for you at the end of the day, and yes you can still shoot horrible shots with great quality, yet the fact remains image quality remains king. You simply can't explain the amount of effort companies put into improving it otherwise or the fact the consumer pays attention to it anyways. And that is what matters. Canon needs to sell what consumers want, and if they review quality, companies need to deliver. The fact canon lags, doesn't make it less important.
come on now.... that's like offering up a lamborghini with a rubber band motor.. I'ts balanced performance that makes a fine car and it's balanced performance that makes a fine camera.... It's lens... and sensor... and processing power and algorithms... and user interface... and ergonomics... and a host of other things too numerous to mention.
I can take a 1DX, put an old crappy lens on it, and ruin the balance of the system. Image quality will be crap. I can turn off autofocus and shoot blurry pictures.... image quality will be crap. I can turn off IS on a handheld long lens at slow shutter speeds.... image quality will be crap.
You need a good working SYSTEM to take a decent picture.... the sensor is only one part of that system so why is everyone so fixated on it?
The Olympus OMD-EM5 has a better sensor than my 60D. I even have a bin of Oly lenses. The Canon 60D has a better user interface, it feels better in the hand, and it has a better selection of glass. Guess which one I use? Hint: system beats sensor...