I don't have anything against the higher magnification scopes. I have a couple on my play toys. But on serious rifles, I think a quality 3-9 or 3-10 scope provides lots and lots of versatility. Imagine this, a 6x riflescope allows the same shot potential at 300 yards as open sights to at 50 yards and is easier, for most people, to aim than the iron sights. What you can shoot at 50 yards with good iron sights should be what you can shoot at 300 yards with a 6x scope or a variable set to 6x. With a 9x, you should be able to shoot with the same general level of vision at 450 yards as you can with good iron sights at 50 yards.
Of course, all this assumes perfect trigger control and follow through and a solid rest. But a higher magnification scope isn't going to afford you a more solid rest.
I don't think there's much of a difference between a 3-9x scope or a 4-12x scope and if it makes you feel better to have the higher power scop, then knock yourself out. I think confidence is a good thing when it comes to rifle shooting. But It always cracks me up to see guys with a heavy barrel rifle and a 6.5-20x scope shooting from a bench and they will swear up and down that higher power allows for smaller groups. Maybe they do but if you can't take advantage of it, then it's a waste. If you have a heavy barrel rifle and a high power scope and you're shooting 5" groups at 100 yards, then... well... you need some help or training. I've seen plenty of guys shoot 1" or smaller groups with a lightweight (not sporter weight) rifles and a little 4x scope.
