I have a V1 and never leave home without it. It has saved my butt many, many times. For the money, IMO it can not be beat. Yes, it is expensive, but for what you get, it's worth every penny.
As others have mentioned, I do tend to drive more conservatively with it, which is a good thing. But when I want to step on it, it's good to know it has my back.
I will be buying another one for my wife's Van. She has a heavy foot, but doesn't realize it.
