It was very easy to communicate to everyone through Airbnb and by text. This made pickup and drop-off easy and flexible. The truck was clean and in great shape when we picked it up and it had everything as described. We lacked for nothing. The truck itself was big but not so big that it felt awkward to drive or navigate around the sometime-narrow roads of the island. The tent is really easy to set up and take down.
We found it comfortable enough to sleep in, but just a heads up that the memory foam mattress is really more of a medium density foam mat. If you are used to camping, it will feel like a dream, but your hips can definitely sink down to the bottom of the mattress and hit the platform below, so if you're someone that needs a lot of support or cushioning, consider bringing a camping pad or something. Also, Kaua'i has lots of wild roosters, so bring earplugs!
The other thing to be aware of is that you will need insurance for the rental. You can purchase this through Jonathan or bring your own, but apparently you will need a written statement that the insurance covers the tent/platform. Some insurances do not cover this aspect as its a non-standard modification to a vehicle, so just check on that if you were planning on bringing your own insurance that this is covered and/or be prepared to pay for the extra coverage.
They offer airport pickup and dropoff for $60. We used this one way and took a taxi the other way after our plans changed around. The taxi with tip was about $60 so the price is reasonable.
All in all it was a lot of fun and I would definitely do it again. It was a unique adventure. I only wish I had scheduled more time to camp at Koke'e state park!