We have been blessed to stay at the Del three times and have visited it on day trips to eat many other times. Prior to our stay in July, the last time we had an overnight visit was 10 years ago. It has been one of our most favorite resorts EVER due to the history and grandeur of the property.
Over 4th of July, we split our stay between the Manchester Grand Hyatt and the Del. We really enjoyed the Hyatt, our first time there. It is right next door to Seaport Village which is a popular tourist destination with shops and restaurants. (SPV is set to undergo a big renovation, but not sure if construction will begin prior to your trip or not). We paid a bit extra for a very large corner room and I would do so again. We liked their grab and go food area in the lobby - Starbucks coffee and tea, breakfast sandwiches, fruit cups, etc. We enjoyed their pool. You would need to drive to a beach or take the nearby ferry from this area over to Coronado Island and get transportation on that end. Overall, a really great experience, and we would stay there again without hesitation. Parking is pricey as it is at most San Diego properties.
Some of the reasons we love staying at the Del is because we can park once and not leave! Parking is very pricey here as well. We love being able to go from the pool to the beach and back to the pool. The beach is beautiful and amazing. Kids love looking for snails and crabs on the rocks. Everything, and I mean everything costs A LOT. The breakfast buffet for our family of four (me, DH, DD14 and DD18) was $160+ before tip. NOT kidding. It was a good buffet, but not an exceptional buffet, so those prices are something to keep in mind. Hamburgers on the deck are $26, extra for cheese. Some of the rooms in the original Victorian building can be quite small and some quite spacious. The overall feel is much different than what we experienced there in the past. It's hard to put my finger on it, but it just isn't the same. If you want to hang at the beach and have some down time, you will enjoy staying at the Del. If you plan to be driving all around the city and checking out different places, then I am not sure it would be a good choice. You might want to stay closer to Downtown or to Mission Beach. Staying at the Del and getting your money's worth, in my opinion, means staying put there to really enjoy the beach, not leaving the property to go do other things around San Diego.
Please let me know if you have any other specific questions.