Whiteline Suspension Q's
 

Bump Steer correction kit, and roll center adjust kit. Do they make that big of a difference?

Installed mine after about a year on my ohlins. Made a big difference in the roll stiffness of the front. Didn't notice as much of a difference with the bumpsteer kit.
Also you should try the steering precision kit. After running the coilovers and 255 tires i lost some steering sharpness, the precision kit gave the super sharp evo steering back.

Shinster, did you do the install for the precision kit yourself? Do I really have to drop the front subframe? Any tricks to the install? If you did it, of course.

Not trying to jack the thread, mind.

I had mine installed for me. I remember reading a thread from some people saying that you didn't need to drop the subframe, however it makes for a much easier install if you do. The guys that installed it for me dropped the subframe. It did make a very noticeable difference so it is worth doing, along with the roll center kit.

On that Precision Steering kit, didn't they have to press out the old bushing? Which would mean removing the R&P, disconnecting fluid lines?

As for the roll center kit.... I didn't think it would make much difference but when speaking with Robi a few weeks back he said he can hop in an EVO and in minutes tell you whether or not it has a roll center kit installed. Apparently it really does help and is noticeable. I have yet to purchase but the voices are telling me to.

I bought it, waiting for my little bro. to install it. yes i'm lazy + he has a lift at school.

Does anyone have a good how to, for quick reference. I just received mine and I don't know where the 0-ring goes.