I think it's important not to dismiss Em's role. She's here to help Lisa. If Lisa was doing so well in her old apt, there would have been no need to bring her here.
It's not a coincidence that the first person who helped Lisa was Em and now she's by her again. A&A know that and i guess that is why Em still there.
Of course, Lisa is the only one who can raise the level of this place but unless she comes up with new ideas (lesbian sex, orgies, etc..). i'm not very optimistic about this place. The stats will go up for some time then with the daily routine, they will go down. The number of new apts will not make it easier. But who knows, Lisa is unpredictable and we could have surprises like 3 days ago.