Kevra,
Yeah I don't understand, 4 hours, that is just unacceptable!
I just installed mine myself and the quality is great, definitely lighter than the stock exhaust. If you are expecting a major change in the sound, you will be disappointed. While it is louder, it is still very subdued which isn't a bad thing, just depends what you are wanting. Personally I would still like a little more rumble, maybe after I add some headers.
The butt dyno did detect an increase in hp but that also could be psychosomatic. All in all you will be pleased with your purchase even if the customer service is lacking
jk