Soldato
Owning a 1080 Ti I still don't feel any need to upgrade to a 2xxx card. I did spot a 2080 Ti yesterday for around £570 new and I was about to buy then I talked myself out of it. I think it was a pricing error as it's back to over £1000 now. Kinda wish I would have given it a go but my mate just went from a 1080 Ti to a 2080 Ti and thinks he's getting 15-20 % better performance which doesn't really warrant the RRP IMO.
There have been some games that have played excellently with the 2080Ti at 4k 60hz where the 1080Ti has struggled a little.
Obviously still an extremely fast card for the price. 30-40% faster from experience which you are typically seeing on the 2080Ti may be worth it. Has been for me but then again it depends on what you value.