Jim's place was a one of a kind experience. We loved how the indoors met the outdoors and we could truly feel like we were a part of nature. The lava rock shower as others have mentioned was awesome, and despite being a rain shower head it had great water pressure. The indoor pond was really neat especially when it rained, and all the glass was really neat for us to be able to take in the outside. We also enjoyed the pool table (which was in good condition) and this was a good location for visiting Volcano National Park which was our primary focus while in Hilo.
There were some drawbacks, however. While the home itself is private, we didn't feel like our space was private at all. Because there is so much glass and the hosts are above (and also walk around the property) we always felt like someone could see inside. This made us a bit uncomfortable and made it hard to feel like home. That being said he was very nice and had open communication which was great, we just wish we had a more private experience. Also with the hosts living above, sometimes it would get quite noisy with loud footsteps, or what sounded like moving furniture/vacuuming.
Aside from the privacy, the other drawback was pests. Because this unit is so open to the outside, there were many roaches and even lizards in the unit. We were unable to keep food out without it becoming infested unless it was completely sealed off (like a jar of peanut butter).
The unit was also quite warm. There is no AC which we knew but there also wasn't much breeze to keep us cool although the host did provide a couple of fans which we certainly utilized. Unfortunately we were still sweating pretty consistently since the fans only cool a very specific area.
Overall it was a very neat place especially for one who wants to be a part of nature. Drawbacks are privacy, noises from above, maybe too much nature with the pests, and it being quite warm.