Bill's place was incredibly close to the Waipio lookout. It served as a good base while we spent a few days venturing down into the valley to enjoy the beach and trail on the far side.
The art store at the front of the building is very cute, and I highly recommend visiting it during your stay.
There is no cell phone reception at or near the apartment, and our experience with the wifi was about 95% uptime. Unfortunately, this could be disruptive if you are trying to stay online to keep up with work remotely, as we were. If you're here on vacation, the wifi was fully sufficient. It never cut out for more than 20 minutes at a time, and was working for the majority of our stay.
Bill was fast to respond to messages, and even brought us dishware that we needed during our stay!
We shared the apartment with a few very shy geckos, who seemed to really enjoy living there!
I would absolutely stay at Bill's apartment again, although I would not plan to work from the location in the future.