This is a great place to stay.
I visited San Diego for 4 and half days, and every day I had to take a bus or an Uber to get to UCSD campus. That worked just fine, since the bus stop is literally right around the corner. The location is remarkably close to a great super market, a place where they would serve great bagels. There is even a Mall at "walkable" distance. So, location-wise, you cannot go wrong if you need to stick around UCSD.
The room was very clean. I am absurdly sensitive to some allergens, like the ones that live on carpets. The place was full of nice, foamy carpets that were very clean, and I had no trouble with allergic reactions. The kitchen is well equipped, with everything you might need and some more. Hanna was very kind to me and even had some cereal, yoghurt and coffee. The bathroom and kitchen were clean as well.
In terms of hospitality, 5 stars are certainly not enough. Hanna is a great host (no wonder the super-host "medal"!), and will be there if you need anything. I did appreciate that quite a bit since I did not know the supermarket was 1 minute away and I ate terrible food the first night.
In overall, please consider this place. It is *way* cheaper than a hotel, the location is more than good enough (really, there are not much closer/cheaper places to UCSD), the place is clean and comfortable and Hanna is a wonderful host.