Running an i7 4790k and a gtx 1070 with the game on lowest settings I never notice myself dropping below 200 fps. I might try moving my settings higher to see if I notice a dip in performance tf2 has just made it habit for me to tank settings in every game. There is some lag when the round first starts but I suspect that will be ironed out. The movement feels good but it definitely isn't the same as source games. It might be because I only have a few hours in the game but the movement mechanics seem more reliant on resource management than skill but there are a few exceptions like the assassins grappling hook that thing is sick.
There seems to be a huge focus on dm so much so that I'm not even sure if they intended it that way but I love it. It feels a bit like tf2 in the sense that no class hard counters another class the same way they do in overwatch.
Edit-played a match with my settings on the high preset and I was sitting around 100 fps so now we know. Hopefully they can work on the performance but it's not like low settings are so ugly they make the game less fun.