I've always said rolling made me less smart. I definitely noticed the lack of smooth communicating! I felt I wasn't able to relay thoughts as well.
This is how I feel.
My experience with MDMA is this:
I first rolled mid-February of last year with a boy who eventually became my boyfriend. I was taking a gap year between high school and college and he had just moved to the city (transferring to a nearby college in LA; he's three years older than me). He had an apartment, but basically lived at my house starting around April or so and then all throughout summer. With absolutely no real responsibilities or obligations, we rolled once a week on average, sometimes every other week and sometimes every 6 days. Our tolerance never really went up (it's higher now, but during our honeymoon phase one pill was enough to get us rolling every time) and it was magical every single time -- this went on for 6 months.
Then, I moved to New York for college in September (and he ended up transferring to a college here to stay with me). With responsibilities and work, and because we wanted to be more responsible with our usage, the frequency of our rolling decreased to around every 3-6 weeks (usually a month). We broke the one month rule during winter break and rolled three times during that period... Not good. But we've also taken 6 week breaks every now and then.
Well, the result of all this is that I definitely think it's a little harder to string together sentences while talking. It's not extremely obvious and probably only really noticeable to me, especially because I've read so much about it on here, but I find that I stumble over words more often than I used to (or at least I think... I can't really remember how I spoke a year and a half ago). My sentences just aren't as fluid. It's kind of shitty. This is pretty much the only thing that really bothers me, though. In terms of my actual brain, I don't believe my intelligence has been affected. I am a film studies major at NYU and got straight As this semester, which is something I didn't even pull off in high school because I was super depressed. I'm capable of writing papers, studying, taking exams... None of that has been affected (thank god). I think my memory is fine as well, though I have ridiculously horrible short term memory while rolling and the day or two afterwards.
It sucks that I don't speak as smoothly as I used to... Hopefully spacing out my rolls more will prevent more noticeable damage from being done. The "magic" is still all there. We can still roll solidly for 4-6 hours on 2-3 pills. I feel lucky that our 6 month binge didn't ruin ecstasy for us.
Hope this was somewhat informative.