Only instance I see them being of use is for rifle hunters shooting longer distances, and mountain hunts.

If you are on a mountain goat hunt, and you see a billy 50 yards (ranged) on a 40* decline....you would hold for a 38.302 yard shot.....

this IS quite the difference....and eliminates calculations on the hunters part in crunch time, not that the calculations are that difficult. This is a step further than the pythagorean theorum, but is still extremely basic trigonometry.