for my uses at 50 - 600 yards what power variable would be better for me? most shooting will be done closer....... 50- 100 yards but 200-400 yards are used as well. sometimes out to 600 yards but not much further. hunting is the main use for this optic with a side order of fun on the ranch. i cant decide between a 2.5-10x vortex pst but am now looking hard at 4-16x vortex pst. can you help?