First question - is there anyone who has these that can offer before and after take? Conceptually I get the point - but can you feel it? And if so, any cons or negatives?

Researched few threads and some were positive but one on another board claimed the valves somehow changed mid range or partial throttle for the negative because it was stiffer?

Context is I'm getting sharkwerks exhaust and evomsit 565 ecu upgrade installed and debating this additional mod.

well i used forge , AP

both were fine and never fail

Did you feel any difference between stock and your forge ones?

well , i installed the upgraded valves because i was afraid from the stock valves to failed

you will notice a woosh sound after letting the gas pedal and it hold boost well

I have a set of Forge? Diverters I will sell you for $125 shipped. Just need them out of here. I can send you pics. I'm 95% sure they are forge brand.

Sorry these were on a 996T. Probably the same part but please verify.

996tt DV's are not the same design as the 997TT DV's.

They won't work on a 997TT.

Well in terms of a big difference no.

All it will do for you is never break and handle higher boost levels as it comes with different springs for different boost levels, so it is good for peace of mind.

AP, Forge, Evoms all the same if you ask me!

Just pick the set that is not over priced.

I use the Forge on my car.

Forge here.

I had issues with one set of early aftermarket diverters where the O-rings melted then leaked. I think the later O-rings were upgraded, but I decided to go back to stock

It can be just a wrong impression but during the 2.5 years of following the 997TT aftermarket progress i have the impression that aftermarket diverter valves is more a US tuners sell marketing because the Euro tuners don't show that must need upgrade. I'm not saying that isn't a improvement over stock, just that the benefit/cost is minimal. Same when adding ic's silicone hoses when still using stock boost or just with a ecu tune, or aftermarket headers with stock or even modified VTG's.

Im with tiago, I think these are a waste of money to consider as an upgrade if yours are not broken.