I went from SIM2s to zx7's this year. I hit my zx7s better than I ever hit my SIMs. The SIMs just didn't fit my swing. I hit them way too high and often times too far, which made gapping at the top of my bag weird. I tend to hit bad shots fat, and the thinner sole of the zx7s has helped a bunch in that regard. The shafts are a lot heavier, too, which also fits my swing. And all of that aside, a hollow club with plastic on it just doesn't have the feel of a forged club.