Whoops...have to take that back. This is a different design than a previously seen version.
This one is actually an extra shock. I will hold my thoughts on it being a point of failure, but maintain my initial assessment that this is eye candy. Adding a fifth shock gives you a cool look and some added weight. What do you gain with this that bump stops, stronger springs, and proper silicone/oil weight and plunger set up can not already give you? The cool eye candy affect.
Do it if you want, but for the money you could get a great set of dual rate springs or single rate springs of a heavy duty nature, some fuel tubing for bump stops, some decent silicone/oil, and have some left over to buy half the shocks for another T-Maxx.