If you have a good/decent computer just leave it uncapped it really won't make a difference. If you struggle to maintain a high range of fps then just cap it lower.
Screen tearing occurs a lot more at lower fps there is a reason why default is at 300 fps since 120+ hz monitors will feel different.
I have a 120hz monitor and the difference between 121 fps and uncapped (300-400) is very very different. Everything is much more smooth and fluid where 121 fps doesn't feel as good. Biggest difference for me is the mouse movement and picture flows/looks better.