Depends on the game... I don't varmint hunt but I could see more power helping with that.

My biggest scope is 14x I live in a very hot climate and have owned scopes up to 32x and anything over 16x or so gets psychadelic about 9 months out of the year.

That being said I would rather have very high quality glass in a lower magnification.

My hunting bolt rifles are topped with:

.223 1-6x VX6
.22-250 2.5-8x VX3//
.257 Roberts 3.5-10x Vx3
.257 Roberts 2-8x Zeiss duralyt
.308 1.8-8x Vortex Razor HD LH (great scope)
.338 Federal 1.5-5x Zeiss duralyt
.35 Whelen 6x FX3
.264 win mag Vortex Viper 4-14 (good for what it is, but looking to upgrade, rifle shoots lights out and could use some better glass)