I've never taken the Old Town Trolley Tour, but I certainly see them around here all the time! Just took a look at the stops, and yes, for people who just want to get a "feel" for San Diego, I think it would be a good way to do it.
Here's the stops, according to their web site:
(1) Old Town State Park,
(2) Cruise Ship Terminal,
(3) Seaport Village,
(4) Marriott Marina/Convention Center,
(5) Horton Plaza/Gaslamp Quarter,
(6) Coronado (Mc P's Orange Ave),
(7) San Diego Zoo,
(8) Balboa Park (El Prado)
Old Town is quite touristy, but can be interesting to walk around.
The Cruise Ship Terminal is right down at the Embarcadero, with a scenic view of the bay, but unless someone wants to tour the Midway (which is an excellent tour, but might be more time than they want to spend), I don't know if you'd want to stop there.
Seaport Village is shops and restaurants. It's cute, but not really much to see there in my opinion.
Marriott Marina/Convention Center - even less to see there.
Horton Plaza/Gaslamp Quarter - LOTS of restaurants in the Gaslamp, so could be a good lunch stop. Horton Plaza is a shopping mall, though at least it's an interesting-looking mall.
Coronado - definitely worth getting off and wandering around a bit here. I'm not sure how close that stop is to the Hotel del Coronado and the beach, which is all quite lovely. It looks like it's only a few blocks to the Hotel del from there, so that's not bad.
San Diego Zoo/El Prado - you could easily spend the entire day just at these two stops! I think it's only worth getting off at the Zoo stop if you actually plan to go into the Zoo, otherwise I'd get off at the El Prado stop instead - there are tons of museums and gardens and other things in Balboa Park to see. Most of the museums charge an entry fee, but there's no charge to just wander around the buildings, and the gardens are free. Though it might be a bit chilly in February.
Hope that helps!
