I have both of these bodies, bought new and taken well care of. With a recent purchase of a Tamron 150-600 G2 and shooting birds I noticed the 7d mkii doesn't render details quite as well as the 5d mkiii. I honestly have not been using the 7d mkii much since the 5d mkiii came in about 9 months ago. But with the new Tamron the additional reach of the 7d mkii is desired.
I understand there are some differences with the sensors:
Crop vs. Full Frame
20.2 mp vs. 22.3 mp
I did a quick side just now trying to keep framing the same with the 1.6x difference. These are straight out of the camera.
I also checked it with my Canon 70-200 2.8 Vii with similar results.
Has anyone else notice a difference in detail rendering or am I having an issue with the body?