I just ran a couple sessions, and I'm now in the camp of "slightly too fast." If I had given out every single XP for all the monsters killed (there were many), and for all the roleplaying (there was a lot), then they might have made two levels. Cutting the XP in half was still too much. I cut it just short of a quarter, then added in some miscelleneous, and they still made a level (which was fine).
Yeah, it was a long, busy session, and if it been spread out over a few days I would have let them have it all, but as it stood...