I'm in the same boat as you. For a professional they very well may be the case. They have so much wheel time and can push a car to it's limits with losing it. I don't go this far for I haven't made it to that level. But from my stand point I fell there better than stock. Especially for what I use the car for. The spring rates a well superior to stock and the adjustable damping they do have may not be the greatest but it works for me. Much firmer which I like. And when combined with my sways, I can drive my car alot harder and corner better than ever compared to stock. But I'm not a professional by no means and I haven't had another setup to compare to besides stock. I'm happy with it for what I do.

So I feel there nothing wrong with the quality of Stance. Everything on my care is balanced between quality and budget minded. I aim for middle of the road and that's what I feel I have. Which is better than stock for me. I have no doubts I personally could run faster lap times with my setup than stock with my level of experience, which is mild.

I don't feel I went wrong. And KW are more surperior. No doubt. There almost twice the price, maybe. There's just different levels of coilovers on the market for all to choose from. And these work for myself. With my level of experience on and off the track I don't feel I that any other coilover would malke me better at the moment till I gain much more track time.

Does anyone know how low and how high you can raise and lower the Z on BC Coils? I have searched and cant find anything.

It always seems hard to find this type of info. But I can guarantee it will lower more than you would need to go.

Anyone have experience with ARK Coilovers, or KSport?

if you don't want to dish out the money for expensive coilover I know a lot of people who are now buying cheap coilover (BC, Stance, etc) and then buying custom coilover springs from swift, it steps up the performance of the coilovers yet doesn't kill your bank account... think about it, its a valid option