Which stock rudders did you have ?

The ones with the alu stocks ? The NACA profiles.

Or the newer ones of AHPC (since 2002) with the DACA profiles.

Personally I dislike the older standard rudderboards and think the newer DACA sections to be significantly better. Still the Blade uses an even better profile (no noice as the AHPC ones) and I'm thinking about upgrading to those.

What profile are the M20 ones. NACA or DACA ?

Wouter