I did my vanos seal around 40K miles, mainly preventive maintenance hence the increase in performance was not noticeable.
Before buying a new DISA you should check if it did go bad :
2001 3.0L 5-speeds,Topaz Blue/Sport+Premium package/Stong-Strut trilogy/Front and rear Bilstein shocks/Rogue Engineering rear shock mount/Ireland Engineering rear sub-frame bushing/CDV delete/Vanos Rebuilt/Conforti CAI/Jim Conforti Shark/LeatherZ Mark2 armrest/DRL module/European Wiper Module/Pioneer AVIC-N4 GPS-Receiver+XM Radio+iPod/iPhone interface+Bluetooth+12CD Charger/ASA-AR1 18" wheels+Michelin PSS/Bi-Xenon upgrade.
Latest mod : 3.73 diff. ... WOW