This is a half review, since i only have the Koni yellow for my rear coilovers. They are externally adjustable. Koni will replace them if ther are and defects and wear. They no longer make the reds, any you see know are old. They tend to give a bit of a stiffer ride, but i have it turned about a 1/4 turn from soft and they are nice (note: there is a 2 1/2 turn in adjustability). If its your daily driver, then I would say the Bilsteins would be better. No adjustments and I have heard its a softer ride than stock but will handle a corner without a sweat.
James