I had a chance last week to listen to a Cayman S with a Tubi exhaust [the same one used for the 987(S)] I was at the track and that thing sounded just awesome; very Ferrari-ish If I do get an exhaust for my car that would be the one I get. I had a chance to have a lap in that car and it also sounded really good from inside the cockpit. I spoke to the sales manager of a Porsche tuning shop who supply both Tubi and Fabspeed (both similar in price) He compared them this way; Tubi closer to F1 cars vs. Fabspeed closer to Nascar. The Fabspeed is louder apparently but I don't like the way it sticks out from the bottom of the bumper ; that disqualifies it for me right away.
For me the question is it worth the price or should I put that towards my next car??
By the way, another option is to have your existing exhaust reworked to make it sound more aggressive - my dealer has done that. I listened to a worked 996 exhaust and it sounded nice.

Check out the sound of the Cayman S with Tubi at the bottom of this page; www.pfafftuning.com