Dave:
I use 2 cameras with 2012ish technology, the 6D and the Sony A7ii. As a tech geek, the A7ii is perfect, having a good blend of features (and IBIS) and image quality. The typical gripes (battery and menus) don't bother me as I rarely shoot more than 200 pictures a week.

I have a number of EOS EF mount lenses which I adapt to my Sony. People tend to frown upon the whole lens adapting thing, but I think its awesome as it allows me to use both systems interchangeably; 2 weeks ago I picked up a used Canon 300 f4 IS and have taken great photos from my A7ii with it.

With the new Canon R, I was hoping for a merging of the best features from the 6D and the A7ii. I want to see more before I invest my hard earned $.