i just put the holtzman kit on my FX this past weekend, i knew nothing about N2O before the instal and never had seen it installed anywhere.
i bought the kit from monker here on the forums and he gave me great instructions, i have them if you decide to go with the holtz kit.
i figured if i could change a track, rebuild an engine and just about anything else then i was capable doing a N2O instal. it was a lot easier then i thought.
i havent got to use it on hard pack but im running a 12 g/s shot and in 2 feet of powder i can get about 75, without the bottle im seeing 60.