Kenne Bell all the way. PERIOD. The Kenne Bell is a far superior product at all angles. Shops will push the other brands because they can make more profit and can sell them over the net. Kenne Bell sells factory direct, or you can buy from an authorized installing dealer. Kenne Bell has been the top dog in power,reliabilty,and on the leading edge for years. Heres a link for some good info
http://kennebell.net/superchargers/gm/Camaro/Camaro.htm Thanks Adam
On a side note, SpankinTime Motorsports does on site installs at an extra cost for those who do not have a shop nearby, or trust. Quality installation by an authorized Kenne Bell installer on site.
I could go on about the difference, but this battle has been done several times already. There is a reason why the fastest guys run KB's.