I am of the belief that lower is better.
If you can see the aiming point is on the vital zone of the intended target you are good to go. Anything more is a waste of field-of-view and a distraction due to aiming point shaking.
I can't see so good at 150 yards at one power anymore, but 1.5 or 2 is clear for me and heavy crosshairs or the 4MOA triangle (6"@150) on my Trijicon is ethical harvesting in my book. If I have a stationary target and time to futz, I can alway crank one up to 4.
![Shocked :shock:](./images/smilies/icon_eek.gif)
The snipers of WW2 made consistent 600m+ shots with 4x scopes. 4x is plenty for any range I consider myself capable of ethically shooting. I do have one 3-9 for that long range shooting I never do.
Great optics trumps power every time. Larger objectives are better than small at low light. Solid shoulder mount and cheek-weld are key to consistent shot placement at any yardage regardless of parallax.
There is no substitute for trigger time. The rule of being able to put x number of rounds on target at x distance where x=yards has improved my marksmanship more than any hardware.
My 2¢