My friend Mike the Millionaire put TORS on his new 2013 Roadster when he bought it new a few months ago. They are OK but don't sound as good as the 3 pipe TORS. I suggest if you have the money to go with one of the others like Staintune, Reband D&D and so on as the list is long of exhaust options. The TORS are a good bang for the buck for sure though.
However, the power increase comes from a modified tune that you need when you install revised intake/exhaust. Consider your needs, budget and options for that along with the pipe change. I recommend Dobeck Performance AFR Plus. It is a simple, easy to use, affordable device that really works well. I have stock intake, TORs and DP AFR Plus. My power gains with just the AFR Plus was about 20 HP and 10 TQ. The Dobeck AFR Plus does NOT require a dyno tuner to install or tune in for you. It is a simple piggyback on your current EFI and you are in control of the AFR. You can make the AFR what ever you want it to be for any given situation or intake/exhaust modes. It has instant readout so you always know where you are. One really good side effect is ... no more burning right leg.
The other thing you need to know about is TuneECU. It is a freeware program that allows you to change your EFI program codes and or make adjustments to the codes. All you need is a laptop and a $20 cable. Very fun tool if you are comfortable with computers.
PM me if you want some details. Or search the forum as there is a wealth of information on these pages.
Bill