Jack's place is a great home base for exploring Williamsburg, and some of Brooklyn's other cool neighbourhoods. The apartment was homey and comfortable, and Jack is a friendly, easy-going host.
The location is great - within easy walking distance of a nice mix of buzzy Williamsburg spots (St. Anselm, Spuytn Duyvil, Fette Sau, etc) and fun dive bars (Union Pool, Rocka Rolla, Metropolitan), as well as having a couple Subway lines close by if you want to go further afield. If you're a light sleeper, it is pretty close to the freeway, so expect some traffic noise, but . . . it's New York. Pretty much expected.
Would definitely recommend.