I've done acid and mdma (both for the first time at bonnaroo last year, but thats another story).
I had an awesome time when I did the mdma. We ingested about 10-15 mg each. I dunno much about the dosing of the mdma but we had an awesome fucking time. I dont know if it was made better by the fact i had taken an acid tab about 10 hours before*. I was on the downslope with that. I was still having visuals if i concentrated.
Back at the campsite and I had had about 4 shots of vodka. Anyway, we took the mdma and then went to the DJ Tiesto show at 3:30 am (lasers, glowstick shit, etc.). Bear in mind it was raining, so we were soaked. I loved the feeling of the rain on my skin, which I would attribute to the molly. The show was extremely intense. It was an awesome fucking time. By the time we got back it was about 5 cause we went to other shows after tiesto.
I was so wired that I didnt even go to sleep. At around 8 oclock am when everyone was waking up (it was 95ish by then and we were in a tent. soooo hot) I ate a brownie for breakfast and then started another day at roo!
*This trip, my first out of 5 this summer, was pretty mild from other experiences on shrooms and other acid. I think the acid just wasnt very strong and I only took one. It was a shitload of fun though, just not as intense as I anticipated.