..............My 2 pennies worth, If you are going to really use it for varmint hunting I would go with the 8X for the FOV, I had a 10X on my Coyote Rig and I had trouble finding them if they were moving...........
Your eyes are better than mineI couldn't make 8X work on a coyote rifle enough better to talk me out of the 12X
Pick one and be thankful for the gift. Hopefully there is a significant sentimental side to the story.