Monitors dont refresh at 60hz they work at 59.xx FPS.
Also GPU often pushes the FPS above 60hz even with vsync on.
The point stands regardless of the Hz. My monitor is listed at 60hz, and shows 60hz in every monitor program I've used, but I have seen them at 59hz too. That has no bearing on what I said.
The only way a GPU goes above 60 FPS with 60hz refresh while v-sync is on, is with OpenGL. Mantle may also allow this, but I'm unfamiliar with its rules. DirectX does not allow it.
The reason the 59 FPS limiter trick was created is ONLY because of DirectX when using 3+ buffers. OpenGL's method prevents the need for a limiter, in fact it creates latency. In OpenGL, if a new frame is created in a 3rd buffer while waiting to display the current image, it will discard that image and display the most recently created frame. This will improve latency. In DirectX, every frame is required to be displayed, even if a newer one is created. As a result, when a new frame is created, the GPU must still send the older frame to the display and hold onto the previous one. This results in added latency.
Anyways, the FPS limiter trick is only useful in DirectX with 3+ buffers while v-sync is on. If the game is allowing higher than 60 FPS with v-sync on, then v-sync failed to turn on, or the game uses OpenGL.
If you are playing a game that doesn't use DirectX, or 3+ buffers, then your FPS limit trick is pointless and may add latency in some cases.