Hi!
I am using 0.41 kg/mm springs in my Ohlins for the 07 EC250 (there is picture in the gallery) and I weigh 83 kg with full equipment. After break in I had to check carefully the sag of the Sachs shock and any front end wash out I was experiencing disappeared. Now the bike is Magic! The Marzocchi felt much softer in the showroom but the difference might all be in the valving. I strongly believe that "you get what you pay for", especially in the case of Ohlins forks.
Leon