I've stayed with Carina a few times now.
She's a very gracious house (an example: when I checked in, I found a pair of earplugs on the stack of towels just in case it was necessary, but it's a very quiet house).
The house is also centrally located: it took me about 7 minutes to walk to the shops on University Ave, and about 15 minutes to walk to the Palo Alto Caltrain station.