I not supercharged but thought I would throw out my thoughts on the mater.
I dont like them basicly because they aren't worth the money to buy new and put on TBI. Most supercharger kits only give around 75 hp(so they say). You can get the same or more, reliable power out of Heads, cam, intake, for a LOT less money than a new supercharger kit.
Personally I would not waste my money on a supercharger for a TBI truck. Because TBI uses a MAP sensor for air flow input you are very limited on how much boost you can run. You cant up the boost to make more power unless you happen to have a flash programer and know how to use it.. Superchargers are better suited for TPI MAF systems.
I guess If you could get it running right for around a grand it might be worth it.
But if you do get it be sure it comes with the chip. They are usually included with a Vortec kit. Your stock chip wont run right under boost.