when you do custom tuning you can change the shift times and transmission line pressures. I dont know exactly how the shift kit works, but when you change the shift times it will shift much faster. during normal driving have the shift time set to change fast will get annoying so most people only do it when entering power enrichment mode. I think .0125 Msec is the fastest you can change the shift time to. if I am going like 20 mph and I go wot I can break traction momentarily when shifting from 1-2, and so I usually turn off my traction control. turning up the transmission line pressure helps the shift firmness, but you can turn it up too high.
