Should you camp on the Big Island? YES! and no. We live in Colorado where there is TONS of dispersed camping in National Forests so we are extremely spoiled, please take this review with this in mind...
Camping on Big Island is...unclear. We got permits through the state site for three sites, Punalu'u, Laupahoehoe, and Mahukona. The camping sites are not marked or indicated, we had to ask locals where we could park. Reviews of parks to follow...
As to our host and the van:
Josh was very quick to respond, he was a good host.
The van has about 6" clearance from ground to undercarriage so you have to be careful about speed bumps and even some rougher roads. It's a Ford with 96k miles on it, so kinda loud, kinda rough, but totally got us around the island.
Josh has truly pimped out the inside. Bed platform is well constructed and truly has everything you need, even a french press for coffee, yay! The mattress gave up the ghost the first night we had it, we tried to tough it out but by the third night we were hurting pretty bad. We are both 5'8" and not overweight and we both had hip bruises. When we talked to Josh he offered to drive all the way from South beach to Hawi to give us another mattress or an eggcrate, so he was taking care of us but we'd had enough. Just check with him to see if the mattress is new before you rent. Totally not his fault, and he did try to remedy it. : )
Oh, the sheets we had were microfiber (plastic). I'm a linen whore so these were just terrible, they held the heat in and we sweated all night. Lucky for us I brought a cotton tapestry and put that underneath, so it helped. This is said for informational purposes only, I know not everyone is "Princess and the Pea" like me and will be fine with this.
Punalu'u is definitely a high clearance vehicle access, which this van DID NOT HAVE. You can park in the parking lot. Sunrise here was Epic.
Laupahoehoe was perfect.
Mahukona was terrible, a tiny concrete pier and parking lot was all we could find of it, and was pretty trashed out.
We went through Hipcamp for three more nights on various properties. Hipcamp wins! It's really amazing to park under the stars up in the mountains and quiet, that is definitely the way to go.