Diana and Juan's place is located on a nice quiet spot, there is a little drive way to the property off the road.
The hosts live on the same property in a house where other travellers can rent a room too. It's great because if you have any issues, the hosts are just a minute away, and you can have some social life with the other travellers. But as the apartment is completely separated from the house, you don't have to talk to anyone at all if you don't want to.
The apartment was very homy, clean, and had more stuff than just the essentials.
2 little drawbacks: options for cooking are limited, if you want to cook anything apart from basics (which we didn't) you need to go to the communal kitchen.
The other thing is that the distance from the house gives you privacy and no noise will disturb you, but it also means that the wireless internet's signal which comes from the house, won't be strong. It is enough for essential Googling, looking up destinations, but e.g. you can't really upload pictures.

In general we were very happy staying there, Diana and Juan and very helpful (they helped us out when we had a little issue with our rental car too). The place is on a great location, definitely rent a car to experience everything the Big Island has to offer!