Does MDMA strength/duration relate directly to amount?

Recently i was wondering why the effects of some mdma pills come and go so damn quickly. It's almost like waking up from a dream and then suddenly it's all gone - back to reality I've been curious ever since munching on a pink diamond earlier this year with minimal effects, and concluding it was simply a shite pill, then seeing the lab results on some euro rave site giving it 79 mg of mdma which is a 'decent' amount.
Is it possible that there is different quality pure mdma?
and if so what's the point of testing the amount of mdma in each biccy - is that just a rough guide? (or the most accurate rough guide we have).
Say a pill tested by Dancesafe has 80 mg of mdma, is that pill definitely going to be stronger than a 75 mg pill? Will it also last a tad longer, or could the mdma in the 75 mg pill have some slightly different properties eg. the way that it hits you, the 'cleanliness' and length of the peak, and the general duration of the pill which might make it a better pill?
Maybe it all comes down to how much seratonin you've got at the time...

The MDMA section in PiHKAL has a little on effects of varying doses of MDMA.
http://www.erowid.org/library/books_online/pihkal/pihkal109.shtml
BigTrancer

i know this is obvious but i feel i have to repeat it one more time.
everybody's metabolism is different and every batch of street MDxx is different.
what is in PIHKAL is one person's dosage responses. and those responses were to pharmeceutical grade MDMA which he made himself under strict conditions.
relating this to pills or powder bought on the street is very dodgy science. not only do you never know how much of a substance is in a pill, you also do not know what else is in there.
but for about twenty years PIKHAL was all we had to go on. now more and more research is being done.
PIKHAL still stands up as a good average to how most people respond to dosage. and no one get me wrong, there is higher authority in my mind when it comes to MDMA than Sasha Shulgin, but even he would, i feel, give these caveats.

"79 mg of mdma which is a 'decent' amount"
God, I hope not. 150 mg would be a good pill. 80 mg is a half dose.

Stone 161 mg is the highest ever recorded dose, i don't know quite how often we come close to that here in Oz, but i doubt every mdma pill you come across has 150 mg. Guess we'll never know.

Got a bit carried away. I would be more than happy with 125 mg pills. 80 mg is a low dose.
From the MDMA FAQ:
Usual doses of MDMA range from around 80 to 160 milligrams (orally), though monks have used lower doses (40-60 mg) to assist meditation, and therapists have sometimes taken similarly low doses to become more in tune with clients.
A benchmark standard dose is often considered to be 2 mg of MDMA per kilogram of body weight (though response to the drug is not strictly proportional to body weight).
FAQ. First Author/Editor: Jon M. Taylor
FAQ Maintainer: Brian Behlendorf

2mg per kilo ... hehe God DAMN do you mean I should try a dose of (2mg*100kg) 200mg next time?
OK then, no probs.

OK, I will take the bait.
I don't think I would go for 200 mg. Use body weight as a guide to calculate dose rates.
I was trying to point out that, in my experience, pills of 75-80 mg are a low dose. You need 1.5 or 2 (75 mg) pills for a good roll.
From the Bluelight users guide "So you've decided to drop: A first time ecstasy user's guide to success" http://p-raves.tbp.mb.ca/art/scroumf-e.htm
The most MDMA recorded to be contained in a single tablet of ecstasy is 161mg.
 Threshold 30mg
 Light 40 - 70mg
 Common 75 - 125mg
 Strong 125 - 175mg
 Heavy 200+mg
 LD50 (Lethal Dose*) 106mg/kg or ~6,000mg
* LD50 = dose which will kill 50% of the tested animals.
Post from Deep via Pinger. "E-verything you E-ver wanted to know"
"The whole reason why Mitsubishi's were pressed out was because over the past few years the quality of pills had decreased significantly. These days the average pill runs about 75mg of MDMA. In 1994 the average pill contained 150 mg of MDMA. In other words you could buy a single pill and split it between yourself and a friend and get the same effect as a single pill today.
People grew tired of this trend and the business suffered accordingly. Mitsu's were pumped out in the summer of last year from Amsterdam to restore faith in E-trade in London. The first generation of Mitsu's were tested at 140mg+ of MDMA. For more info check out the article that Mixmag did this year on the Mitsubishi phenomenon."
I estimate that the recent run of turbos were ~ 125 mg.
Cheers
Stone

XSI11V , If you're talking about the diamonds that were around june period , they were actually 79mg MDA , not mdma (from www.eve-rave.ch )...and yes , altho these turned slowly to purple they were absolute SHIT. i still have a few left that i'm not going to take , thats how bad they were! minor buzz , never came close to peaking...
Now , if you look at the grey fish , they had 73mg of mdma , and oh boy , they were superb!! so nice and clean , a good four hours of fun on those.
As was said in above posts , it also depends on what otheer shite is in the pill etc...But as for your question , is it possible that there is different quality of pure mdma , well , no ,cos pure is pure , and we certainly don't get pure pills what a shame...

thanks sweetleaf - that was the site I got the figure from but didn't realise it was mda - but that explains my experience on them perfectly !
Like you, in my experience 80 mg of mdma (eg. the fish) has always done the job for me, and explains why many of us chose to split the pills years back when more often than not they were 150 mg Fair enough as most of us payed $60-70, so it all evens out I guess.

Hey guys - are the diamonds you were talking about a dark pink?
I had one of those, and a mate and myself did not have a very nice time on them at all. We couldn't be bothered talking or dancing, and never really peaked. I was lucky in that my dd let me swap the spare one I had for some good stuff.
The ones I had were really well pressed, and dark pink. It would be good to see if they were the same ones - might answer a few questions I had!
Thanks guys,
Voodoo

yep voods those were the ones - really nice looking press.
I remember popping one and waiting - my head just went a little fuzzy and that's it. So i went for a cruise coz cranking my stereo as it always brings on a pill for me Once i got to the city nothing had changed and i could scarcely bother to drive home.