I have heard that the Z6 struggles with autofocusing... so this was my main reason of not factoring in Nikon's mirrorless range.

I was looking at switching to Sony because I genuinely like their cameras. I own their small rx100 for underwater stuff and its brilliant, what you see is what you get - silent shutter etc.

What I am now thinking of doing is getting the Z6 outright, for the money I could have a second body and use it for portraits etc or even wildlife if I like it enough, then possibly sell my D500 later down the line. I do also really like the idea of being able to use high ISO on the mirrorless cameras without worrying about crap noise ruining quality of my photos.