I played OAMN twice in a few days and it's been a joy to run! The second time I leaned more to follow the Investigators' input as opposed to trying and guide them towards an idea I had as Host, and it flowed better.
On a "technical" note, when the characters choose to let the Terror overwhelm them in exchange for something "powerful or secret" from the Host, I found that giving them a Clue worked better.
Aside from that, both sessions have been a blast, and the system really highlights the game's mood. To the point that we now refer to it as "By the gods! I have it!"