The pornhub blog is surprisingly good reading every once in a while. They take their data analysis seriously.

I’m similar to you. Used Dvorak for quite a while but switched back to Qwerty. I never really had any speed gains but I definitly had a lot of comfort gains.

Those are not nearly as conveniently located for left handed use though. Having z x c and v all easily reachable with my left pinky on control and my right hand on my mouse tops any other benefit of another keyboard layout.