I would love to give a honest review of my experience as follows.
The host and her husband are fantastic. They both are extremely friendly and easy approachable. The rooms are situated next to next and obviously there will be some acceptable/bearable noise, which is fully acceptable. Getting such a room in a central location is not that easy and it is from my personal experience. People who just come and stay for a while can write a negative feedback but the reality in SD is different. San Diego is not a cheap place and it is super expensive.
The room has wonderful windows and adequate 2 fans and people who feels it is hot can use it and there is no restrictions.
The floors have a good carpet to reduce the noise while people walks on the floor 
Regarding the bathroom usage, we need to respect others and plan our time and if you do that, it is not an issue.
There is a sign on the bathroom door to flip whether it is open/occupied. It looks like few guest are careless flipping that and that caused some discomfort to them (others try to open the door when they are inside). The host has also put a note inside the bathroom to flip the sign that sends a message to others who come and try to open the door.
Overall the place is good and you will never repent for staying at this wonderful place for a decent reasonable rate in super expensive SD.
Note: First time I writing such a a detail review….. phew……..