It's been a few weeks since I installed it. It's excellent. It eliminated the whistle from the oem one that seems it can't handle anything over factory psi and it seems to have eliminated the dead 1-2 seconds where boost is just recirculating after letting up on the throttle. It's way more fun to drive while rev matching.
Install was a light PIA because I didn't remove the oem turbo intake tube. It's very much in the way but it can be worked around. I wish I'd have ordered the intake tube and just done it all at once. I also used a small hand vacuum pump to keep the diaphragm of the Perrin compressed against the bypass body. It's much easier to get Allen screws in place this way.