This is a great option for folks wanting to be super convenient to the beach! Literally a 3-minute walk, plus they provide beach chairs, umbrellas, various other beach activity paraphernalia/toys, beach towels & blankets and a wheeled cart to haul it all with you. Sand on the beach is super soft, water (no surprise, it's the Pacific) is frigid. There's a sort of sidewalk that spans many miles along the beach -- perfect for a stroll, leisurely skate or bike ride. And the Belmont boardwalk area is a 5-minute walk, which has lots of rides, a 100-year old roller coaster (it's refurbished), putt-putt/mini golf, etc.
As for the space itself -- everything is very clean and feels comfortable and modern. Full kitchen with all the appliances and everything you need. Couch is not super comfortable but I can't complain (you don't want to spend all your time at the beach on the couch anyway). They have a TV with all your typical streaming services available. The bed was VERY comfortable -- I think it's some kind of memory foam mattress -- we slept great. It was nice to have a free spot in a garage to park our rental car, although actually getting into the spot is a bit tricky/takes some practice. There is laundry available for $1 per load but we didn't use it. There is an elevator which helps because the apartment is on the 3rd floor.
I only have 2 complaints about this spot: 1) there is no air conditioning, so you have to rely on open windows and box fans to cool the apartment. It worked well enough but there were some nights that were hotter than others. 2) due to the former, you have to keep the windows open at night, and the apartment is right on the main street in Mission Beach, which means that people and cars will be LOUD all night long and there's not really anything you can do about it. (Can't really submit a noise complaint on a passing car with a loud muffler. Can't close the windows without being stuffy and over hot.) Also I noticed their elevator inspection expired in 2020, if that's the kind of thing that bothers you.
On the whole, we had a great experience and would highly recommend this place for anyone who wants a convenient and comfortable spot right by the beach.