i have a pretty much stock truck.
i got the CM stg 3 mpg, with the cmgs controller. love it. two stages, two nozzles. i use the #2 and the #10. the first stage is my "normal" driving. i have my second stage set to not come on, less im pretty heavy footed, or im pullling something.
in a hot tune, pulling some hills by my house, with 22k of round bales and trailer, it is real easy to hit 14-1600*. i would normally not do that, pulling in a hot tune i mean, but i wanted to see what the water would do.
turn the water on, same hills, same tune, with the next load of bales, trying to get it hot, will not break 1200*. i physically could not get it hot.
im like csi, i didnt get it for power, or mpg. its hard to judge a mpg gain with it, because it so variable when it comes on. if your light on the go pedal, because your trying to get good mpg, your prolly not hitting the thresh hold of the water anyways, and if you do, your not there for long.
that said, i can say, in general, i MIGHT have picked up 1-1.25 mpg. in all reality, negligible gain.
to set my controller up, i turn two knobs. i can set all 20 different parameters, with just the two knobs on the face of the controller. no additional "stuff" required.
if for some reason you need more control over your system, i think it was thug who had the laptop version. fine tuning crazy with that. i dont know about it though. he would have to comment on that.
i think it took me about 4 hours to put the kit in. most of that was trying to decide where to put stuff. pump, tank, controller, stg 2 solenoid, flow sensor, etc etc. the actual install time was about 3 hours. me and wiring diagrams occasionaly feud.
if your looking for "feelable" sotp power, its doubtful you will get it with water. or meth/water for that matter.
charles uses some water soluable cutting oil in his water tank. swears by it. something about water washing the oil off the cylinder walls, and leaving condensation everywhere in the intake tract, and getting noticeable blowby with straight water. the cutting oil he said made the blowby go away on its own. there was more to it than that, but i could not find the thread he posted that in, and thats the best i could do from memory.
hope that helps.