I'm very happy with it. In terms of affecting the cars outright performance, as such, I cant really say till I've been on the track, strip or Dyno with it - but Ill eat my hat if the car isn't measurably quicker in all situations. On a fast back road run for 150 miles it felts quicker for sure but in terms of lap times I don’t know how this will translate – Im thinking 4 tenths over a 1 minute track lap?. The DMS has given the car a different dimension and is one less reason not to rush out and upgrade to the next GT3....HIGHLY RECOMMENDED - Im a very satisfied customer! This is not a cheap product and infact the most money I have ever spent on an exhaust set up (and its only headers), for any of my cars ever. That being said its a quality 321SS unit that should last the life of the car, it is a direct fit for 991 GT3RS, 911R and likely the forthcoming 991.2 GT3, so there is a large secondary market if I should sell the car or I can take it with me to my next GT acquisition...and there is also a GT4 set for those who like to row their own gears on track!
Thanks Jamie & Charles for your excellent product, your excellent service and all your help in getting these to me. I look forward to your GT3/4/RS exhaust tips next! ~ Mark, Australia: 991 GT3 Race Headers