It is a bitch to remove and install. The termi system is stainless and offers little weight saving over the stock system, just 2kg, It's an awkward exhaust to build as termi found out. They start with a massive 70mm tube size which ends up looping in and out of the silencer at just 40mm tube size. This can not and does not give good power results, it is very awkward to build a system that gets rid of this problem due to space and db level restrictions but we are on it to try and come up with a better solution.
It won't come cheap.
You can fit the systems yourself, some bolts are awkward to get to and the heat shield is a pain along with lambda sensor removal. Problem is you need to slacken off the shield to get the sensor out and so on.