I've been doing MDMA for ~7 years now. Always adequate breaks, never taken more than 100-150mg and it always feels like its stronger than the time before! I'm pretty sensitive to the stuff, I'm one of those people that has crazy comeups where I feel like I'm going to literally die but once it breaks I'm in heaven. Never fails to knock me on my ass.
Never had a hangover or "comedown" from it either. I pretty much only take it in combination with LSD though since I'm usually at a music festival and they're just too good together to not take both!
I met the love of my life at a music festival pretty much exactly 2 years ago. MDMA has definitely helped us open up to each other, communicate, bond and become stronger together. And yeah, the sex is amazing. We dance the night away like the night we met.
Not nearly as long as you, but it doesn't feel as if its losing its magic anytime soon whatsoever!
I see a lot of my friends lose the magic as they gobble away caps over ~3 day festivals, I try to tell em but they don't listen
A friend of mine got the magic back after taking 1000mg in one night and then abstaining for an entire year.