Gee even at level 85 with a full 10 man raid Halyon was still hard to do, and we weren't successful though we did make some progress on it.
Transitions from Phase 1 and 2 were relatively quick though as expected people died a lot to cutter, but the big killer was the Mark of consumptions in the twilight phase because when they're in melee they are terrible to try to avoid. And running out of them is still hard!
Anyway, if we lived a little bit longer and did a little more dps inside we could have made it, but the number of circles is nuts! Outside is not much of an issue, it's relatively easy compared to doing inside, since it was the twilight realm guys which were dying all the time.
Anyway we gave up at 2230. We did OS after that with our now routine and laughable zerg pull strat which means no clearing and pulling every mob in the place which gives crazy times and also I finally got my mount! Yay!