I've had an NX setup fitted to a previous car and it was great till the nitrous solenoid went down (better that than the fuel!!!!) it was a well made piece of kit all hoses are braided unlike the wizards which look cheap an plastic. also the bottle looks much better an more professional IMO.
Don't know what extas are availible for the wizad kits, but NX has a MASSIVE range. including safety switches that cut off the system if it runs too lean (which I would advise as thats when things go bang)
Having said all that, if an when come to fit another kit I'll be going for the ZEX wet system.
It's only a restricted kit, I think only options are 35, 50, an 75bhp, and the purple bottle looks a little camp, but eveything looks good quality well made solenoids, braided hoses, nice machined valves etc. It's the easiest system to set up I've come accross, and it has a "smart" box that controls both the fuel an nitrous, so they're in the correct proportions, . Very safe AND they're cheap esp if you order from the states... or were untill the pound fell on it's arse lol.
Hope this helps
Mark