We didn't see Greg and Isabel a whole lot while there but when we did they were incredibly friendly and very helpful. Also very quick to respond whenever we messaged.
The place is comfortable, clean, light, has everything you need, and it's an amazing location to explore the city from. Williamsburg itself is wonderful to walk around, and the apartment is a 5 minute walk from train links to Manhattan and the rest of Brooklyn.
Overall a great stay and would definitely recommend it (and do it again)