In the last two weeks or so I went to Scholomance with a pickup group 5 times. In 4 of these 5 cases we either abandoned before reaching the first boss, Rattlegore, or directly after that fight. Yesterday was the 5th attempt, and we totally cleared out Scholomance, killing every boss including Jandice and Kirtonos (in the correct order to get me 2 quests done). I felt as if I had won the pickup group lottery.
But of course it wasn't a *real* pickup group. While technically we had 5 different guild tags, I came because I knew the guy organizing it, and he knew the other players in the group as well. A network of online friends is as good, if not better, than a guild for forming groups.
The third quest I got done in Scholomance was Dawn's Gambit. I don't know if I did it wrong, or if there is a random factor. But when I placed the item that was supposed to destroy all undead in the room, it only turned the students into skeletons, which swarmed us en masse and wiped us. I think staying outside the room while placing the item might have been a good idea. :) Or the "with a little luck the item will destroy all undead" part in the quest description was meant literally, and we just didn't have a little luck. Anyway, the reward is a *very* nice staff, Dancing Sliver. But I was a bit sad that I lost the roll for the Skullsmoke Pants, because they are very rare, and I don't think you can kill Vectus without having the Dawn's Gambit quest.