Exhaust Cutout

I was looking at Exhaust Cutout from pfyc.com I guess it bypasses the muffler whenever you switch it on. Has anyone tried this out? How much louder is it and how much HP gain do you see from it? Info will be appreciated.

it will sound like you have no muffler. you will most likely lose hp if you do it a lot, because the engine will loose backpressure. and you better hope the valve never breaks other wise youll have a permanent exhaust leak

I've read nothing good about these:

http://www.grandamgt.com/forum/showthread....&highlight=qtec

had a few links with bad reports on these breaking, but this is the only one that works at the moment.