I used to do this all the time. It is AMAZING!!!!!!!! I have literally stayed up rolling for DAYS doing this (through repeated dosing of course). I would never do this now, but several years ago when I was smoking a lot of meth I was around a lot of people who had good MDMA pills cheap, and I went through a lot of them.
We would smoke meth, get good and high, and then start snorting x pills 1/2 at a time. Maybe 1/2 a pill every hour or so at first and then slowing up to the point where you can maintain the roll my eating a pill every couple hours. Of course we were smoking meth the entire time as well.
It is ridiculous how good this combo feels. Expect mad rushes, lots of tingles, great inner warmth, intense urges to dance. Drink lots of water, be sure and make yourself eat at least a little, and take vitamins. At the time I was not concerned with the potentially neurotoxic effects of this, probably because the meth convinced me that I was invulnerable. i haven't done this now in 4 years but right this minute if someone but them both in front of me I wouldn't tell them to screw off...