Having examined the files in comparison with those of IDX, MK3, D4s and others, I would say there isn’t really much of an improvement in IQ and low noise performance. Canon hyped it up too much. People looking for near FF performance had better be more realistic.
In my eyes, the improvement of iq over the 70D is slight. It appears to let in a wee bit more light and perhaps a very slight noise reduction, very slight.
With advanced post processing, the raw files can be rendered much better.
However, there are a host of new features, notably the much talked about improved AF, weather sealing, 10 fps amongst others that might sway many towards this camera.
Is the price justifiable? Depends, if you always wanted FF and about to make a choice on a particular DSLR, then mouth-watering models like Nikon D750 might be more enticing offering you the best of FF with crop sensor ability. If you already have Canon lenses and looking to pursue birds and animals in the wild, this is it!
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.