I've found that in the vast majority of cases the difference between high and ultra is negligible yet the framedrops are quite massive. If it isn't framedrops, it's stuttering, loading, etc. I don't use it at all even on a 1080ti.
For example I was playing Max Payne 3 earlier today, on the highest settings it's a locked 144fps but if you do some 360 degree turns at the start of the game you will get hitching and stuttering without fail. Turning the game down to high eliminates it altogether.
I think for a lot of games, especially modern ones in the last couple of years, ultra tends to be the same as high but uncompressed and lossless, it's really not worth using. A decade ago you'd see an enormous visual difference but it's not quite as evident anymore. For the frames it kills, ultra is never worth it.