A friend of mine works at a smoke shop and while he was on probation with random urine screens, he was smoking the Spice products. The Gold and the Diamond were the best. I was able to try some of his for free. First of all, it tastes like shit! If you like the taste of good weed, you will be disappointed. Do NOT smoke marijuana in your bowl until you clean it of the Spice residue, it's really nasty.
The high was decent. I only smoked a few hits but about 5-7 minutes later I had a decent buzz. It resembles a marijuana high, maybe mid grade but not dank. I don't know if smoking more would have increased the intensity as I had good pot at home and hated the taste of that shit so I didn't take any more.
Surprisingly, the high lasted quite some time, about 3-4 hours. I think that could be the saving grace of this stuff as it is more expensive than the real deal, but it does last a lot longer.
If I was going to be drug testing for a job or needed to stop smoking MJ for other reasons, I would consider buying this stuff, except they aren't selling it anymore but supposedly have a replacement product that is just as good. I can't remember what this new stuff is called but when I try it, I will give you all a smoke report.