Can't help with your questions. I know when staying for an extended period that apartments are nice but just wanted to give you a 'heads up' about points and qualifying nights at the ExecuStays. You only "earn 2.5 points per dollar on all qualifying charges regardless of the length of the stay at Marriott ExecuStay, where every 3 nights stayed will award members 1 night toward Elite status... Only points, rather than miles, may be earned as a guest at ExecuStay." You may not care about points and qualifying nights but I passed on the ExecuStays because of this.
I lived in San Diego for 15 years. In order to answer your question about which ExecuStay to stay in, I'd need a little more information from you. What kinds of attractions for adults do you like? Clubbing, quiet walks on the beach, street fairs, artist colonies, symphonies, intimate music venues? A list of places I enjoyed: LaJolla Village with its many art galleries, funky shops, wonderful food and overall ambience. La Jolla Shores beach. When the tide's out, you can walk 5 miles north to Torrey Pines State Beach. The San Diego Wild Animal Park has several tours you can take ranging in time from 2 hours to 4 hours. The San Diego Zoo is a marvelous wonderland of valleys and hills, with the animals in natural settings. Not to be missed are the Sunday afternoon organ recitals in Balboa park. Take the ferry to Coronado for the day. Tour a Navy ship on the weekend. Sea World has many exhibits adults enjoy more than children do. You can check the individual ExecuStay locations to see which have work-out clubs. Safety is not a concern. The ExecuStay can tell you which neighborhoods to stay out of. A terrific web site with a very complete list of what to do in San Diego www.thebestplacesinsandiego.com. Let me know if you have more questions. I loved living in San Diego and miss it very much. Have fun for me!