I know a number of guys who use 150 gr, equally just as many that use up to 180gr for whitetails, it boils down to accuracy and situation why they choose what they do. Obviously accuracy is moot, so I would then ask yourself what the situation is and pick the appropriate bullet accordingly. ie: If your shots are likely to stretch out 200 or further and/or aim for the boiler room (ribs) then 150 might be better due to it's slightly flatter trajectory. However if you don't expect to shoot longer ranges or most likely 100 yardsor so and/or may take a through bone shot the 165 maybe a better fit.

Either will get it done on whitetail if the guy squeezing the trigger does his!