I have the RM NoS setup, and although he doesn't "sell" it anymore its a great setup.
Im not fond of progressive units, or switches under the gas pedal. I want full control of when the nos is on/off, so I use the horn setup.
Ive had the NOS in my car for ... hrm 2+ years now and have NEVER had a problem. Ive burned the bottle from full to empty in a single afternoon.
I recently had a compression test done on my engine, all is in order. I have 93,000 miles on my car and it still runs like a champ.
The ONLY thing I didn't like about NOS is the fact that its limited use. From full to empty is roughly 2 minutes and 15 seconds worth of NOS (which don't get me wrong, is a long time if you really think about it, you tend to use it in 5-6 second spurts, afterall yer only really using it from 10-100mph right??????) however at 30-35 bux to refill the bottle, it adds up over time.
I must admit though that the NOS in fun to play.
I emptied bottle after bottle when I first got it, and now find that I rarely use it, simply because I just don't have the desire to pull the bottle out to re-fill it
call me lazy...
I still get that urge every once in a while getting on the freeway, or running up against some schmuck who is gockin at the car and won't let me pass or manuever so I open the bottle, punch it, and evade the situation.
All in all would I do it again? Probably, because considering the alternative's, NOS is a "in-expensive" fix for raw power on demand.
As far as spinning the tires... in first gear, no problem 3k+ RPM's, hit the NOS and I break free, almost everytime. I run 18x10's on the rear, so thats a lot of rubber to break free, but it still does it.
In second gear? Not as easy to break free, it hooks up and pulls hard (2nd is by far the best NOS gear in my opinion).
One suggestion, if you do end up buying the kit, spend the extra money and get a bottle warmer. It really does make a HUGE difference in performance due to pressure. I live in California, land of the warm weather and I often found that the bottle still wasn't warm enough to put out 900+ PSI until I used a bottle warmer, then I always had pressure, hot, cold, didn't matter the car pulled strong because the pressure was consistant. Pre-bottle warmer, there were days when I was at 700psi and it was not even worth arming the system the performance was so poor.
Hope this helps
-B