Good: great location next to the pool, garage is well stocked with beach toys and equipment, home has a great layout with tons of seating for hanging out just about everywhere. The BBQ was a great feature that we used several times (more bbq utensils would have been nice).
Bad: we had a terrible check-in experience. After traveling all day and arriving exhausted at 11p, the door code did not work, evidently because it had not been changed. Worse was that we could not reach the host. We sat stranded outside the unit for 45 minutes frantically calling and trying to figure out where we were going to sleep that night (sleeping on the beach sounds cool unless you have a 3-year old child with you). Eventually the host responded with a code that worked. The bottle of wine a few days later was a nice gesture but considering the insane nightly price we paid, it left a bad taste to have to pay for that frustrating, high-stress first night.
Aside from that, the other 12 nights were good. The host was pleasant. Check out was smooth and they accommodated a two hour late check out, which was very helpful when we transferred to another Mauna Lani unit.
Overall experience: bad first night, the rest was good.