Tein Flex has the following features:
1. Adjustable ride height
2. Adjustable pre-load (this is a great feature)
3. Adjustable dampening (16 settings)
I also bought the EDFC, an electronic controller box which controls 4 servos mounted on top of the coilovers. This allows on-the-fly dampening adjustment from inside the car while driving, pretty cool. On the softest setting, the ride should only be slightly siffer than stock, but on 16, we are probably talking shopping cart.