I have experience buying a rebuilt vanos solenoid from Beisan systems ( i think thats the name) I installed it in July 2012 and my M3 has been pulling hard since!! I do have a tune, Catless headers which does make a difference. I am head to head with E90 335i with a JB4 tune on low boost... 11 psi?. That should give you an idea on how I pull now.
Feel free to ask questions
2005 M3 Jet Black SMGII
Exterior:ZCP/CSL Wheels Carbon Fiber CSL Trunk. Remus Exhaust. Black Exhaust Tips. Matte Black Kidney Grills and Gills. Engine:AFE Intake, TurnerMotorSport Lightweight Pulley Power Kit, Supersprint Headers (Catless) 1 AR20 and 1 magnaflow resonator on stock mid pipe. Supersprint X-pipe Activeautowerke Tune.
S85 Swap in progress est: Late 2013 :)