Geoff's place is tucked away in a quiet and fairly private neighborhood on the north side of Oahu. The views are dramatic, the private beach (do take advantage of it!) is a gem, and the place itself is stylish, clean, and easy to find. I went with my girlfriend and her parents and overall we enjoyed our stay.
That being said, we had the bottom unit of the two guest units. Our upstairs "neighbors" were staying before we got there, and they had access to amenities that we couldn't find (eg: beach chairs were nowhere in sight). Also, if there's a way to improve the sound-proofing between the units, the stay would have been even better - we did hear/feel movement and vibrations early in the morning and past quiet hours; it sometimes felt like someone was moving furniture upstairs!
Other than those things, this is a great find if one values the chill quality of the North Shore/wants to escape Waikiki. I'd come back.