Ok...Im kinda embarrassed for asking this, but what exactly is a shift kit? Does it make shifting faster in an auto?

 

makes it shift harder, and less slipping

 

It re-routes the flow of transmission fluid to provide quicker, more firm shifts.

I have one and love it, a similar end result is doable with an electronic hand tuner (Diablo or SCT) but a shift kit replaces the stock parts with stronger, thicker aftermarket parts, creating longer life of the transmission.