Well, I have heard that the GHL will quiet down a little bit as it goes through some heat cycling, but I can't imagine it would be a huge difference.
I've thought about the GHL a lot myself but I use the car as a daily driver and don't always want the extra attention.
It's funny, driving the car through the winter, with the top always up, the sound is reduced to nothing and I realize what a big piece of the experience the engine noise is. It seems to be worth about 50 hp!
