Hi bigbulls!
I have the VX-II 4x12x40mm on a 17HMR and like it very well on that particular application. However, on my whitetail deer rifle, I have the VX-III 3.5x10x50mm. I just recently traded a Vari-X III 4.5x14x40mm in on the 3.5x10x50mm. I didn't care for the adjustable objective feature on a scope for deer hunting, but it is desirable on a gun such as a 17HMR or on a varmint rifle. Also, like you, I thought I could use the higher top end power but found out that in low light conditions of dawn and dusk, that the magnification above 8x to 10x was pretty dim because of the limitations of the 40mm objective. So if I were you, I would bypass the learning experience that I went through and get the 3.5x10 model in whichever objective size suits your needs. You will be much better served by it on a big game rifle. Plus, the VX-III's have finger adjustable windage and elevation, no coins necessary! The VX-II line is very good, but the VX-III line is much better and worth the extra $$ in my opinion. Hope this helps, good luck!