Damn, it's been a while since I've seen you around these parts! Good to see an old username pop up again.

I no longer spray and haven't in a couple of years or so, actually. The nitrous is still hooked up, though. It hasn't been used in so long and with my Z at 151K miles, I'm not sure if I should even spray to see if everything is working still.

 

I have about 40,000 miles on it, had about 20K when I installed it in 2008. I only spray at the track. 150HP at motor, about 110 to wheels. I go through 2-3 10lb bottles a year. So far the only thing I notice is that the timing is a little loose. I hear pinging sometimes on regular gas (No nitrous being used). I just haven't tried playing with the UTEC to fix the ping. I change the oil every 3000 miles and I only use Royal Purple synthetic. Haven't found any metal in the oil, so that's a good thing.
These motors are pretty strong, so as long as you set up the nitrous the right way and don't misuse it, they will do well for a while.
I'm looking into building a whole new motor now with twin turbos. Been pricing out parts. The 4.1 stroker kit and block I'm looking at will run over 5-grand alone. Looks like with turbo's and new build, it will be about 12K. But it will be a 500+ WHP beast.

 

LOL. With that many miles, I'd be afraid to but the pedal to the floor.
These cars are fun even without nitrous. I still wouldn't buy anything else, except for a GTR. I've been thinking about selling my 1968 Chevelle SS396 I've owned since 1982, to buy a GTR. I could probably get close to the amount of the GTR, but I have a feeling I'd regreat it for the rest of my life. My boss sold his 1971 Chevelle SS454 convertable on Barret Jackson a couple years ago. He was into it for about 40K, he got 253K for it.
I was watching the auction on TV and couldn't believe he got that much for it. He regreats it, but he had to sell it to pay off his ex-wife from their divorce. Damn women..... LOL

 

^ Yeah, I refrain from spraying now. Hell, I don't even know if my solenoids both work still (well, I know the nitrous one still opens). I still race every weekend just as I did when I first bought the car and I still love it.