So, mine's been sitting in bottles for 6 months, now, and I'm still not at all pleased. At this point it's carbonated enough to drink, but not enough to form a real head. It took about 3 months to get to that point.
This was actually my first all-grain beer, which was probably a bit of a reach for me. At the time I brewed it, there was no D2 syrup available anywhere, so I used the soft brown candi sugar. Looks like the D2 is available again, now.
Mine wound up around 1.090 (I think I used slightly more sugar and slightly more grain on purpose as I was actually hoping for something closer to a Rochefort 10).
I fermented it in my apartment which I don't really heat during the winter, ambient temps around 60. The fermentation was the most explosive I've ever seen. I had a blow-off tube fitted, but even that kept getting clogged with yeast. The lid blew off the bucket once. Fermentation temps got until the 73 degree range, despite the cold apartment. Almost right off the bat, the banana odors were so strong, my wife asked if I were baking banana nut bread!
I'd read about this yeast giving off banana notes. These were not notes, but entire banana symphonies.
About a month after bottling it, it tasted like banana-flavored rocket fuel, and was still flat.
Now, 6 months later, it takes like mellow banana-flavored rocket fuel. It's still too harsh, and out of about 25 batches of beer I've brewed, it's the only one I won't serve to guests.
Rochefort is my favorite beer in the world, and since others have had luck with this, I'm going to keep trying.
Since I've been brewing all summer in my un-air conditioned apartment, I've had good luck cooling fermentation temps by keeping the fermenter in a large cooler filled with water, and I add ice as necessary to keep the fermenter temp where I want it. Next time I brew the Rochefort, I plan to do the following:
1) Maintain the temperature at or below 65F.
2) Add more yeast when bottling. I know some of you guys have had luck without doing so, but I haven't.