Yeah, I also stopped using the powertwist belts, it slipped to much was the biggest issue that I had. The damper does provide a consistant compression rate, I noticed to get a good shift on er3 u need a higher shock rate then with a variotop. Think the ramp angle makes a bit of difference. But yeah, the damper helps with belt slipping since the initial compression is higher then with a spring which ends up being to soft starting off, in my opinion. Another option I've played with since that photo is using a doppler spring over the gas damper and using lighter weight on the damper. U then get the intial higher rate plus the increasing rate of a spring with a nice dampening effect. Anyways I'm saying that having a just a spring works ok but dampened setup works better for me.
-naz