I live near San Diego and I don't go down there. Yes you can find some wonderful deals on certain items, but you have to really have to be aware of conterfeits.
If you are going to shop for some items, then it may be fun. If you are going for the pure tourist aspect, I wouldn't go there. I would continue going down to Rosarito.
If you do go, don't stay the night. In fact plan on being out of there long before the night even hints at being close. remeber that you will be in a foreign country. The laws are different. Also, before you cross, pay the extra money for Mexican Insurance. Even if you are walking across, it will help if there is a medical emergency.
Good luck, be safe, and have fun.