supercharger kits

Anybody with any experience with bolt on superchargers as to end result?

Thinking of putting on one of these:



http://magnacharger.com/gmtruckradix.htm

have one on my 2k 5.3 ecsb silverado

i don't have dyno or track numbers

the kit came complete with all parts needed except coolant for intercooler

install was pretty easy, had good directions and took me a weekend

gives a great increase in power from just off idle to redline