I use a 100shot with a bottle heater and purge. Had it dyno tuned it got 368hp I think. Hits hard out of the hole. See my signature for 1/4 mile times. I only have used it on the track. Has been a couple times I have sprayed on the street.
Pros
cheap power
If you don't want to use it shut it off
It's safe in low doses (after a dyno tune).
It makes a cool PSSST sound with the purge valve
Cons
You run out of bottle your done
You can blow up the motor if your not carful or if your to care free
(do your research on how big of jets to use)
It's not always under your right foot like a super charger or even better a turbo
You can find good used kits for under $800 with two bottles, heater and purge.
Any other questions just pm me ill answer them all if I can.