Grip size is one of the basic fitting fundamentals that can matter for any level golfer. Even if you just play for enjoyment, know the ballpark size your grips should be. At the very least, it may improve how comfortable you feel playing and at the range. The difference between the .580 and .600 is very small. Add one extra layer of grip tape and that will increase the size of the grip you bought to what the original .580 is.

580 is a smaller inside diameter than the 600.  I prefer the 580 with four wraps underneath essentially making the grip feel even larger.  I do not prefer the 600 since it does not have as much cushion (thickness) as the 580.  Either is fine however it comes down to the feel you prefer as I have pointed out.

Good Luck!