The right scope is ALWAYS better than iron sights. Near/far, fast/slow, makes no difference. They are better. But you have to have the right scope. If your question is "how close is too close for a 3-9x" then that can answered. Even today I ran into a too close situation, not the first time either. With a 3-9x a running critter at 5 yards is tough. At 20 yards it's s chip shot. Unless you are gonna be having deer run in front of you at 20 yards or under then your 3-9x is fine. Personally I'd look hard at a 2-7x. Great for close, plenty of magnification for 300 yard deer.