Im very impressed with the performance of this fork. The RC3 cart is buttery smooth. You can tune the damping with the oil height as well as plenty of adjustment on the rebound and LS compression. I can also get the shim stack tuned to my riding specs.
I would get a pro to mess with the shim stacks.
Yes, the 55 is a wicked fork when paired with the RC3 damper!
I dont think you would need the shims messed with as with oil height and oil weight you can adjust the fork easily. I always ran a mix of 10wt and 15wt oil in the damper to give more damping for my big arse, ahahhahha Its like changing the shims in an easier fashion.
The new 55 RC looks like the perfect fork for all I do. I like the air spring as I dont have to worry about coil sizes.