[RC-Monster Mike]

Both shock sets are very good. The Prolines are high tech and, as stated, are a little heavy. The Integy shocks are the best looking in my opinion, as well as being extremely smooth. the purpose of the piggy back is to add extra oil volume. This keeps the shock oil temperature cooler (heat sinks on the piggy backs help, too), and therefore keeps the dampening action more consistent as well. as the piston travels up and down inside the shock, the friction causes heat. Like most liquids, the shock oil will get thinner as it heats up, and the piggy backs help minimize the effects of this.

There are also several other shocks that work well, too. I have the Traxxas big bores on a couple trucks and find them to be a good shock as well (although they don't look as nice as some of the others).