My Lancair IV ESCO strut is circa 1997, and went back to the factory some time thereafter for a rebuild while I was building the fuselage.  Then a big time delay, and then finally flight status in April 2007.  It is heavily damped making it a bit difficult to make a tight U turn on our dirt home strip (minimum braking, and I like to use next to zero power to prevent rock damage), but otherwise has been fine with no hint of shimmy even when operating with strong cross winds. 

I have made up a turntable for the nose gear and plan to measure the torque at the next annual inspection and compare it to the latest Service Bulletin.  I think the damping is well above the recommended levels.  I see no reason to exchange it.

Fred Moreno