Bitubo 40mm fork upgrade?

[rutgery]

I'm looking to improve the feel and handling of my sportified Cali 3 with the 40mm Bitubo forks without adjustment, and I'm wondering what other people have. What's the best way to upgrade them?what about Bitubo vs wirth springs? New springs and/or dampers? Or toss the forks and replace them?

[Turin]

I've has great luck with http://www.racetech.com/ . Go with springs and gold valve emulators.  I've done this with 2 bikes and it totally transformed them.