This VRBO fit the bill exactly for me & my husband. We came to San Diego to scout apartments for a move, mostly in the North Park/Normal Heights area. The location cannot be beat; I don't think we drove further than 5-10 min to get to anywhere.
The RV itself is really cute. It's small, obviously, but it's just fine for two adults. The queen-sized bed was pretty comfortable. The kitchen is spartan but serviceable; we made quesadillas one night with fresh tortillas from the farmers market on the host's recommendation. The bathroom was, well, what you would expect of a bathroom in a camper. The outdoor space is great - we had beers out on the turf every night because the weather was so nice.
Parking is on the street but was not too difficult to get (parking at the end of the block usually). We rented a car, so I'm unsure of how easy it is to take public transit to get to places, but there are bus stops nearby. The neighborhood was relatively quiet and we never felt unsafe, even walking a few blocks to the 7-Eleven after dark.
The host was very responsive to messages and even offered to save a parking spot on the street for us on the first night. If your goal is to come to San Diego to spend time in North Park/Normal Heights, this is a great stay!