Originally Posted by Manito

3:2 is the ideal if you are using a 2.9 base speed or slower weapon. Haste procs, like quick shots, or haste casts like Rapid Fire or Dragonspine Trophy, should lower the attack speed enough to give you 1:1 while still using the same 3:2 macro. You shouldn't need a separate 1:1 macro rotation during hasted periods, 3:2 should drop down just fine to 1:1.

2.10 is the maximum speed that you can effectively use the 3:2 at, if you are at say, 2.17 (default attack speed for an unhasted 3.0 speed BM hunter), you will get closer to a 2:1 ratio (very bad).