I had the pleasure of attending Santee's fireworks this year. Hoping to avoid the crowds and parking chaos in Ocean Beach, La Jolla and Downtown San Diego I decided to try to frequent the Town Center Community Park in Santee. To my suprise it was much easier to navigate and less harassment factor than any of the other locations I have attended.
Plenty of places to sit under the stars considering the multitude of ballpark fields. There was almost no problems finding a place to park, walk in and set up camp. If you want to sit in one of the bleachers you can.
Even better you could have shown up early and went to the fun part with the food, rides, games, and live music. It was a carnival like event that was free to walk around and experience the excitement. You would need to pay for the extras but overall it was a great time.