I would really like to, but from what I've read they all leak eventually. The silly thing about this is that lots of higher end cars (and Chevy's) come with factory exhaust bypass valves that don't leak. If anyone knows of an OEM-quality cutout, I'm all ears.
I've had QTP's cutouts on my S550 for almost a year with no leaking. I just love being able to choose when I want to make some noise or stay low key from the fuzz. Also I've had QTP on my old turbo eclipse for 5 years with no issues. Maybe I've been lucky but it's worth every penny in my eyes