Let's be clear at the very beginning - if you're looking for a hotel, look elsewhere. Dolphin is a nice and clean motel, but yes, it's a no frills, very basic motel. If you're OK with that, then don't look any further. With the price you simply can not beat, Dolphin is the place to be in San Diego.
The rooms are very clean with white walls and white bedspreads, and equipped with a fridge and TV. The walls are literally paper-thin, so you can hear absolutely everything that's going on around you. I could hear a guy in the room across mine snoring! It's very hard to get a decent sleep in here. The ensuite bathroom was OK, but the shower was very small and cramped, especially if you're tall. Breakfast (coffee, tea, muffins, bananas and yoghurt served in the courtyard), strong wi-fi and on-site parking are complimentary. The staff is very helpful.
The neighbourhood is great with some nice restaurants (Point Loma Seafood, The Pearl...), sushi place, Starbucks, McDonald's, Subway and Jack in the Box nearby. Great brand new Ralph's grocery store is also near.