I've been at Mission Bay, Campland and Chula Vista resort. All are the same distance from downtown. Here are my opinions on them:
If you're just staying inside the resort and not venturing outside, then Chula Vista is a cleaner and quieter site. That's probably because of all the signs that they have at every opening on the ground, telling you not to do this and that. Venturing outside the park after sunset is not recommended. The public park between the site and the waterfront is crowded during the day and is a gathering spot for suspicious crowds after dark. Not to mention it is littered with leftover craps from the parties and picnics that went on during the day. The waterfront looks nice, but too dirty to get into. The price is way up there for its location, and they charge for every little thing, including wifi that doesn't work all the time. We stayed here for 2 nights after reading all the high ratings that we saw, and we vowed never to return to this place.
Mission Bay is more fun. It's still a well maintained site. You can walk to the beach and do all the water activities. It has a nice bike path around the bay, and a huge park across the facility to walk around. It's well lit around the facility, and since it's between a couple mobile home complexes, it's not really open to the public and is not crowded. You can watch fireworks from across the bay every night. Price wise, it's about $10 less than Chula Vista Resort. We've tried a few other sites around San Diego in the past year and have decided to just stick with this plate in the future.
Campland is noisy, crowded and seems to cater more to the partying people.
