Karen and Joshua are really nice people, and their two kids are adorable. They received us warmly, gave us lots of advice and told us interesting stories about themselves. Also, they tried to keep it as quiet as possible in the mornings, which is surely a challenge with two energetic little kids.
Their apartment is really close to the subway (about a 2min-walk), which will easily take you to other parts of Brookly and Manhattan.
There are two things that you should be aware of, however: the neighborhood seemed a little rough to us, so that you should be careful at night. Since the walk from the subway to the flat is so short, it only bothered us the first night, when we were a little surprised at the number of policemen and shady people on the streets.
Also, as it truthfully says in the description, the room is very small and a little problematic for two people with big luggage. It is not a place where you would want to hang out very much; which should not be a great issue either, if you know it in advance and plan to be out and about all day anyways.
The whole apartment is rather small (it looks more spacious on the pictures), so that you have to feel comfortable with "intruding" on the family's much used living room, since the guest room is right next to it.