Overall, Corey's place is great for the price! However, we'd recommend two people maximum for a good stay. In more detail:
A couple drawbacks:
1. Two people, not four, is the maximum that can comfortably stay in Corey's place. This is because of the couch bed. Its seating surface is much harder than typical mattresses, making it uncomfortable to sleep on.
Furthermore, the couch is extended by placing the back cushions on a pullout tray. Since the couch is L-shaped, part of the "bed" will be its seating surface, part of it will be the back cushions. The two have wildly different softness—the cushions would be quite pleasant to sleep on, if part of my body weren't resting on the harder surface.
We had no complaints with the actual bed! Definitely comfortable enough for two people.
2. A few other reviews have mentioned the wifi, which we can confirm is very slow and prone to disconnections. (Measured less than 1 Mbps using fast.com).
But it's not as bad as it seems! If you connect to one of the wifi networks with the same name but with a suffix like "2.4G-EXT", the wifi will be much faster (measured around 30 Mbps). I'm guessing those are extenders, which greatly help the bandwidth.
The good:
1. Corey's place is in a fantastic location. We never had trouble with parking. The neighborhood is very quiet (occasionally we heard party noises, but nothing too disruptive).
It's also very close to SeaWorld (~15 minute drive) and many other San Diego attractions. The view is also very nice, giving a bird's eye view of the canyon from the backyard.
2. The kitchen is well-furnished—it includes an electric stove, pots and pans, a wide selection of knives, a double bowl kitchen sink, and a fridge/freezer with a drinking water filter.
3. Corey was responsive to our messages and is a very nice person! He promptly provided us extra bedsheets and blankets when we couldn't find them.