Oh yes, Universal Is a fun park. I am not sure how it compares to the one in Orlando as when we go to WDW there is so much to do at on property we never leave the WDW compound. My family would go for 12 days in early June. I would then get an annual pass and go solo for the Christmas season in the World. I could have spent my visit going to see the various resort decorations, But I could not imagine spending no time at worldshow case or Magic Kingdom.
The SD Zoo is very hilly. But there is sure a lot to see.
There is so much more to Southren California then
Disneyland glad you are taking adventures to see as much as you can of that area.