I will wait for the R7 as most people know from the YouTube reviews the animal eye detect is pretty damn good and that is what we are paying for for £1,349 ( plus free adapter, worth £199 ) and we will not get that tech in a cheap ish camera body from canon. I have a Sony A6600 which has Animal & Human eye detect AF and it is pretty good, however what I do not have is tele glass from Sony, i.e 100-400, 70-300, 600 prime etc as I only have few E mount glass.
I do have canon EF glass, 70-300L IS USM and Sigma 150-600 C which I have mounted to the Sony A6600 via sigma MC-11 adapter, and they work very well. AF is slower than on a canon body and AF is not quite edge to edge, though still very workable.
The pulsing on the Sigma 150-600 is on all R series cameras and an issue Sigma know about, as I phoned them a few weeks ago and I was told in single shot mode the lens works fine. It is the AF system on the R cameras is the issue with the 150-600 C
main reason being Canon do not release technical data to third party lens like Sony have done for their E mount.
I will still continue to use my 150-600 C as for the money I can not get any canon with that reach for the price. Even the RF 800mm f11 is apx £1,100 which is still very good value for the reach, however no fast enough for most sports & wildlife !