I am sure they will be much better for some people, less so for others and a disappointment to some others.
Of either camera (D500 or D5), all we can say is ...
It's just a camera - one that improves several features over previous/earlier models - but then most new releases do that, don't they?
Almost certainly not worth jumping brands and ditching a heap of lenses you might already own by another manufacturer - it probably won't improve your photography. I'm not sure where you are coming from 'Simes' (Simon?).
We don't know what you're shooting with now, how well you understand it and make use of it, nor what shortcomings you hope will be addressed by one of these cameras (which one?)
We cannot answer such a vague question any better than that, I'm afraid.
Cheers, Dave