The comparison here is 2080 (starting at $640) and 1080 ti (starting at $630).
Also, neither of those deal with reflections, one is deep learning super sampling, where you output 4k from 1080p deep learning super sampled that appears like 1900p with the performance of 1440p, and the other groups blocks pixels together to be rendered at the same time, further increasing performance.
Best value for the money. 1080ti it is enough for me until prices come down on RTX. I own the EVGA 1080ti ssoc and run it overclocked. EVGA also has the best warranty out there covering any overclocking. I think it is 3 yrs as well.
Edit; now reconsidering my position on this after learning that the FFR and brainwarp is now in beta and may only work on RTX cards. May have to drop some coin earlier than expected on the upgrade to 2080ti. Will follow this new development Pimax has just released.