[yuhaoyang]

A lot of people say that the systema red piston shatters easily.
shock transfer system, I would assume some of the shock produced by the spring is transfered through that and into the reciever. It also looks like the two gold tabs are springs, so some of the shock will be absorbed by that as well. I'm not really sure either since it's a realitively new product, and I do not personally know anyone who uses one, but that youtube video is pretty convincing lawl; in theory it should work pretty good as well. Your choice really. ARS sorbo stuff have been prooven to work, I have a set in my gun.
The bushings and piston will only cost you like 30 bucks, depending on which ones you get (don't cheap out on bushings), and it will last a long time. If you get a completely new mechbox right now, you end up with a working mechbox in good order as a spare. Also it seems like some people say that the pinion gear on the systema motors have problems now and then, but I really have no idea, and I could very easily be wrong. You will have to consult others or research yourself.