The shock bladders are great. I bought them like 5 months ago and the only time i rebuilt them was when i had to change the oil weight. They are just as smooth as my tamiya shocks that i have to rebuild at least once a month. My suggestion is that instead of using foam between the bladder and cap, just make a small hole in the plastic shock end and dont put any foams. This factors out the need to match the rebound between shock pairs.
Eric-