Just fitted a blow off valve adaptor to my standard car,will give you an honest view so you can be a bit better informed.
cost $13.00
Ebay.
tools required,flat blade screwdriver and a 5mm alen key.
time to fit around 2.5 hrs.
YouTube videos say can be done in 20minutes,if you are a fully trained race mechanic would still take longer,as the blow off valve is obviously close to the turbo that generates lots of heat the 3 studs are well sealed into the casing,access is very limited and I have small hands.it is not a technically difficult job just takes time and be patient.
does make a sound but obviously you have to be hard on the gas through the box,mine is a manuaa.very little lag before and even less with the adaptor fitted,and I am a synic but can tell the difference.
Is it worth it.
Simple answer is cheap,good result,can be a bit of a pain in the rear,don't regret it and at the money from Ebay got to be worth a go,a few $and a bit of time,go for it I say.
And not a single fault code has shown.