AC broke just before we arrived, and the inside unfortunately stays significantly warmer than the outside. Once the AC was fixed (which took 1 day), there were also some snags with the correct operation of the Nest thermostat (we were locked out at one point and couldn't adjust it).
That said, the host was very accommodating given the AC issue and went out of her way to make sure we were happy with our stay, leaving no complaints about the way she handled the unexpected broken AC. All in all the customer service was excellent, it's just too bad we had some bad luck with the AC (this was the weekend after record-breaking heat on the West Coast, which pushed the AC unit too far).