About a month ago I decided to try out the latest quiet version exhaust from fabspeed. "Version 3.5" is what I call it. This system is based on the gen 3 cans but with more fenestrated tubing and aerospace packing in the can itself. The previous quiet can was a physically smaller can with a strap mount welded to it coupled with different internals, which yielded a quiet, subdued sound. I initially tried this exhaust back in Sept and it was too quiet, almost stock. I needed an exhaust that was louder than stock, but not to the level of the gen 3, which can be very loud (too loud 4 me). The new system also uses the latest HJS cats with conical inlet/exits (same ones used by EP,Tubi,CG,etc).
I installed the new system a month ago. The install is straight forward, I chose to do it wiithout removing the bumper or ICs. This process took me about 3 hrs 'skin to skin'. I also substituted OEM clamps in place of the v band clamps at the cat junction to avoid loosening/resonance.
This is NOT a quiet exhaust, it is a moderate sounding system. The sound is really good, very air cooled porsche like. It is about as loud as the Tubi system. Absolutely no drone or resonance whatsoever. The 'regular/loud' generation 3 had an increased intensity at about 2800 RPM, this is gone, probably due to the cat design change. The sound is very similar to the Tubi, just deeper.
The system really lets the turbos spool up quickly, I'm at 1.2 bar in no time!
Overall, this is the best system available for the 9997TT in my opinion. The sound/performance is on par with the CG tuv sound/Tubi systems, that's the best analogy I can come up with, but you gotta hear these systems for yourself.....NO CELs'
Here are some random pics of the install, the final position of the tips and the large OEM clamps that I like to use.

 

Nice write up Chris. I wish I had the technical know how and patience to do what you do. Glad to see that Fabspeed is making better systems. I had their system on my 996tt and really didn't like it. Have you had any other systems on your car other than FS?

 

Only stock, but the 997tt gen 3 system is nothing like the old 996tt systems.

 

Very true. Nowhere near the same. I tried the 70mm gen 3 on our 996tt 3.8 car and it's spot on. All the 997TT ones fit well and have no drone either as you said.