I used to think the 7DII might come pretty close to FF in IQ and high ISO performance. Until last November, when a thread in CR completely disillusioned me. Next thing, I bought a 5DIII and sold my 7D and I've been kicking myself ever since that I didn't do it a year sooner. So yeah, I totally see what Jrista is talking about [although not cool to use 'trounce' in APS-C vs FF (that too same generation), Jrista, not cool].Agreed!
I am lucky that I didn't end up waiting for 7DII and be disappointed.
If IQ was my only concern, I could walk into the local bestbuy and grab a 6D for less than what we expect a 7D2 will go for. There is no way short of physics defying magic that the 7D2 will beat it... But for me, I really want a more capable AF system and after playing with the touchscreen interface on a 70D, would like to see the next generation of that too... Hmmmm...... 5D4?
And this is where it gets interesting. If the AF system gets improved that hopefully means more keepers as was the case with the 5DIII and 1DX. So technically the IQ of the camera could be improved with a better more accurate AF system...as we know, Sensor IQ is nothing if the image is fuzzy to start with.
One needs to look at the system and not just one feature. If the 7DII gets an AF system on par with 5DIII or 1DX then that systems is more desirable than a 6D. I would expect a higher keeper rate (At least for subjects that are in action). For me, having tasted the sweetness of the advanced AF systems, I could never go back to the old school 19point or less. I would be disappointed, even if the sensor was noiseless.
Thats just me and buying a camera based on sensor alone is an amateur mistake.
I did not realize how bad the AF was on the 60D until I got into birding and tried a borrowed 5D3..... now I can't imagine getting another camera without a great AF system. My ideal camera would be the sampling density of APS-C and 5D3 (or better) AF system... this is why I am so keenly waiting for the 7D2 and why I did not even consider the 70D...
I picked up a 7d a year ago for a backup camera (again...after selling one to buy a 5diii). If i had to buy one now it would be a 5diii or 1dx if the wife let me. However as a backup the 7d is ok and well its a backup. My intent was/is to replace it with the 7dii. I could easily just replace with another 5diii but i dont feel the need to rush out and make a purchase. I Wou,d rather wait and see if the 7dii has an improved af system...will certainly have better iq than the 7d.
On top of that i have magic lantern installed which stretches the 7d capability a bit and keeps me occupied while i wait for what seems like an eternity for 7dii orders to start. However if the 7dii ends up being just another 70d with enhanced video then i may defer to another 5diii.