Visit the San Diego Safari Park (owned by the zoo) when you are staying in Carlsbad. It is due inland from there. Be sure that you go first thing in the morning as it can easily be 20 degrees hotter than right on the coast. Should you want to visit one of the California missions, it's an easy drive from here to San Juan Capistrano. The mission complex is quite extensive and give a good idea of the work that the Padres did with the Indians.

In my opinion, do not bother with the La Jolla property.

I would choose the Marina property over the Sheraton Suites purely based on location. Symphony Hall is in the midst of the city. Sheraton Marina faces the harbor so has a pretty view. It's also much easier to take a car in and out there.

(I've not stayed in a one of these properties so take my comments as being geographic-centric.)

Look in this thread for some information about restaurants near the Carlsbad property:
http://www.flyertalk.com/forum/starw...ps-needed.html

And perhaps there are some snippets of useful info here:
http://www.flyertalk.com/forum/starw...-children.html