Just my 2 pennies, here...
H&Rs thicker spacers include their own studs, IIRC, but the thinner ones, like the 5mm, do not.
We had a guy at an autox event last year lose a wheel in one of the turns. Not sure how much damage he did to the brake disc, etc. Anyway, he was using spacers, and I'm not sure he had them on correctly, but the buzz seemed to be that if you use them, you need to take extra care. Longer studs are available, and perhaps not a bad idea.
