The difference between 60hz and 144hz is huge. I have a 165hz 1440p monitor so I always try to keep it above 100 fps which isn’t hard with a 1080 Ti. As far as locking the FPS I don’t bother since the monitor I use has G-Sync (yes it’s worth it) and pretty much any FPS fluctuations look smooth as butter. On games like Overwatch I do limit the FPS in game play to 160 because if I don’t then I will get 200+ FPS even on epic settings at 1440p.