I LOVE it! I got the expansion this week and although I haven't had a request to stay over for a few days yet (looking forward to it) I have had one Sim ask a Sim in my household to move in. And I let her. Their relationship bar (the green one) was very high, almost full and considering that the Sim that got asked and the other two in the household were all 'starving' students so getting a fourth one to move in that had already graduated (via the game mechanics as this was a townie) and able to get a high paying job makes all the difference.