But the extra reach is nothing, I never understood the hype of Crop Vs Full Frame Reach. I went from a 70D to a 6D and i will gladly say the reach difference is like half a inch on the image, I even put a 1.4x Extender on the 70D and the difference is again, hardly anything and for what it cost ($500), it's a waste of money.
I thought about getting the 7D Mark II for Wildlife but i might just keep the 6D as Image Quality will be better. But i do want to see RAW samples at High ISO, It's looking like the 70D ISO performance but it might be a stop better.
If you've never understood the hype of the "reach", then you've never been reach-limited. Because it does make a huge difference. Other environmental factors can still come in play to ruin your image (atmospheric haze, heat distortion, etc...), but the advantage of higher density pixels can't be denied given the right conditions.
If this wasn't true, then there would be no point for Sony to make a 36mp sensor (which crops down to 16mp).