Currently have the IZ 7S in my 5 wood as well. I hardly ever game it since my confidence level is not as high as it should be. Put this way, I have a VF 7S in my AI Smoke Max 3 wood and have no worry about it off the tee or the deck. But the IZ 7S in my AI Smoke Max 5 wood I agree with you I feel like I have to swing harder to get my number.
Did you stick with the TR red in 5W?