Camera movement is much smoother in performance mode, though the drop in visual detail is noticeable compared to what you see at 4K. (mkaugaming.com)
If you'd like to use the most aggressive and high - performance options when on battery power, switching to High Performance mode might help a little. (howtogeek.com)
Also, the performance still seems to be the same, and we used the phone for a couple days on Performance mode to check it. (phoneradar.com)