I personally had a TC5 and I can tell you that the new shocks are terrible, they leak and you must check them often. I have an E4 for racing this year and I would have to say the the E4 shocks blow those out of the water. I have not had to do anything to mine since I put them togehter months ago, unless I am changing the oil. They have kept the set rebound very very well and have not had any leaks at all.