No system is going to play most games at 120-144 FPS, but those high refresh monitors are always an advantage.
1) With V-sync on it won't stutter as much when you can't hit 60 FPS, as there is less wait between a refresh when it misses one.
2) Without V-sync, tearing is far less noticeable, allowing you to leave it off and have lower latency.
It might not be worth it to you, but that's another question.