I want better low light AF, better ISO handling, more DR, I want manual focusing assists via an EVF.
If I buy another 5dM3, I feel like I'm taking a step in the wrong direction.
Well if you are being contracted to shoot a wedding you do need another body in the very unlikely event of failure; the likelihood of failure is so low almost any body that took your lenses would do.
I think that if you wait you may get what you want; I suspect Canon is looking at an interchangeable viewfinder body, that could well be the 5DIV. After all, Canon are in the business of selling cameras, they must come up with a product that makes prospective purchasers buy, whether it is really required or not. A body that can either fit a normal high quality pentaprism and use the mirror, or lock the mirror up and fit a really good EVF in place of the prism would be interesting. I could see this coming on the 5 series first as this is a general purpose body, whereas the 1D series is more for those that still really benefit from an OVF anyway. And the 5 series was the
video dslr. This would also put the DPAF to good use; I always thought Canon would do more with this given the complication compared with a few DP scattered about the sensor.
Then skinflints like me might think "maybe I should move this 5DII on now and get a 5DIV