Way back in the day (2000-2004 for me) 2 decent pills was perfect for a good night out for me. I'd start with one then have the other in halves at the 1 and 2 hour mark. Due to both tolerance and a general decline in the quality of your average pill I'd happily eat twice as many now and wouldn't flinch at double/tripple dropping.
However... I have taken considerably larger doses and over done it on a couple of occasions and it's not fun by any stretch of the imagination. Learn from my mistakes and use in moderation. Unless you are satisfied that you know exactly how strong your pills are then I highly suggest you don't double drop.
EEEEEveryone knows that once the bikkies are wearing off, and where continuous re-dosing is not going to get you anywhere, it's time for a shottie & noice bump of k... or coke if you prefer... or hell, even do both - the old cK1 speciality :D
I find these substances are way more effective at keeping the buzz alive... while giving it a pleasantly different 'off chops' feel as you begin to taper off for the evening/morning
It's fun :D in small doses mind you
just enhances the psychedelic buzz in your head, makes you dance uncontrollably & also you are unable to feel your feet if they have already copped a thrashing on the dancefloor! you of course are left writhing in complete and utter pain once it wears off (if you wear high heels when out dancing like i do)... but, stilettos aside, it's just a great way to taper the festivities off as k has no real comedown in small bumps... and it brings the MD back in little waves as well.