As chris said, you need to be aware of the need to retune your ECU, but having said that, the nissan computer is a very good unit. requiring only a small socket to be soldered in the car becomes tunable to a fairly high state. and you still get to keep all the lovely features like cold start, idle control, knock sensor etc.

the Z32 requires a re-wiring of the AFM plug and has a much better resolution for reading the airflow, but only really is worth doing if you have done other mods (turbo especially, but injectors, exhaust, intercooler etc.) it will not run without a retune... which can be done by some places over the phone...sort of. whats your current setup and what are you wanting to achieve?