Our 2 share a room. They both go to bed at the same time so no dramas there. They don't usually wake each other in the night but as soon as one realises that the other is awake in the morning it's all on. On the mornings they are in seperate rooms they let us sleep in for longer.
My only concern is that Imran doesn't seem to feel much ownership of the room - he always calls it Yasin's room. I would feel more comfortable if I thought that he felt it was more *his* space.