Pro of N20 (NOS is a name brand for nitrous oxide systems) is cost its cheap to get on your sled.
Con of N20 is you have to under clutch for it, over gear for it, its not that easy to hit the button in tight spots, it has to be ready either a warm bottle or a full bottle and valve opened. Big con is your out of the juice when you need it.
Its something that will work but you have to prepare for it and try to save it. A 2.5lb bottle lasts about 10-20 shots for 3-4 sec a shot and thats it.
Boost is way better, only con is its $$$$