Having just upgraded over the weekend from the very same card as you to a Inno3D GeForce RTX 2080 SUPER Gaming OC X2 that I managed to pick up from the B grade section for £450 I have to say I am impressed with the performance bump.
I was hoping to hold off until the new 3000 series cards are launched but with all this world turmoil I am not convinced it will happen this year......
I didn't really need to upgrade but just had that itch and I couldn't shake off, you know the one
Having put my 1080 Amp Extreme on the Bay last night I have already got bids on it covering around half of the upgrade cost and it still has 6 days left to go!
I did a few benchmarks on Superposition-2560x1440 at fullscreen using extreme settings
GTX1080
FPS Min 13.80 Avg 16.56 Max 19.2
RTX2080 super
FPS Min 25.87 Avg 31.00 Max 35.44
I play on a a Predator 3440x1440 100HZ Gsync monitor and would say it has given me around a 30-40% increase in FPS on Modern warefare (not using ray tracing) and its also allowed me to up the settings a fair bit on RD2.
For the price i paid and for the performance boost it has given i might even be able to skip the 3000 series all together.
Hope that helps you decide