TL;DR: Great unit, great location, little to no hot water in the shower.
Pros: This is a great, private place in a safe neighborhood close to the airport, the Mission Hills and Hillcrest area, and Little Italy. Shirley was very responsive and the unit was clean and as advertised. There is no AC, so if you're visiting in the summer time you may want to keep that in mind.
Cons: As others have noted, the hot water in the shower lasts about 60 seconds, then rapidly gets colder until it's on the colder side of lukewarm. As a result, it's nearly impossible not to take a cold shower. I mentioned this twice to Shirley, who stated that Southern CA is under drought restrictions and therefore, "we take short showers." This seems to imply that the lack of hot water is a forcing mechanism to ensure that renters don't take long showers and therefore increase the host's utility bill. I've stayed in other Southern CA Airbnbs and this has never been an issue. Given that I was paying to stay in the unit, which is listed on an Airbnb site at a daily rate the host has presumably determined is fair and would cover expenses, I cannot understand the lack of hot water. I am not a CA licensed attorney but I believe lack of hot water also goes against the implied warranty of habitability.