I was on the fence when dropping about $600+ on my 980Ti Amp Omega when it released. She overclocks really good and out performs 1070s. It was the most I ever spent on a single GPU, even more then I spent on two GPUs for SLI builds in the past.
I haven't seen a reason to upgrade from this 980Ti yet. Mostly due to prices having gone way up for top end cards. Any higher end cards that have come out haven't been worth an upgrade in my opinion.
Spend around $600 or so for a GPU that gives around 15-25% performance gain of my 980Ti.
Or
Spend upwards of $800-1200+ for a GPU that gives about 40-60% performance gain over my 980Ti....eh, no thanks. I love gaming on PC, but the prices for GPUs are retarded. I can't bring myself to spend 2-3 months worth of car payments or a mortgage payment just for a high end GPU.
If by some chance AMD or Nvidia (hell, even Intel) brings something out in the 2080Ti performance range and is priced reasonable at under $500, then I'd look to picking up something new. Until then, guess I'm too cheap to drop loads of cash just so I can do maybe 8-12 hours of gaming a week.