I would absolutely recommend staying at Bea's place.
The apartment is large (compared to NYC standards, at least) and clean, with a minimal design but some nice art/decor to add personality. We felt right at home in the spacious but cozy guestroom, and the bathroom and kitchen had space available for our toiletries and food/drink, respectively. The bedroom has an operable shutter so you can sleep in when getting over jet lag, as the room is nice and bright during the daytime.
Bea is an incredibly friendly, generous, and accommodating host. As one example, she spent time to explain to us everything we would need to know for the apartment, including how to use the kitchen appliances and laundry. During our stay, we had a chance to sit down with her and chat at the table in the back garden, and had a great conversation; but we also felt comfortable doing our own thing around the apartment.
Over all, it was the perfect place to crash after long days and nights in Berlin.