Haven't had an Nvidia card since AGP days, but my Radeon HD 7870 is just struggling too much at 1920x1080 with modern games, AND the GTX 1070 is too bloody irresistible.
I have two secondary systems that are also due for an upgrade...these will probably get a midrange card of some sort and I'm watching to see what happens here by year's end. One is used as a sort of HTPC box, and for that one I'd really like to stick with AMD.
The last PC graphics card I've had is a Geforce 3 Ti 200. I nearly upgraded it to a Geforce Ti4600. I'm one of those people who was always constantly waiting for the next big thing and never ended up buying anything.