I think in the medium to long run that SFH will outperform multifamily in San Diego.
1. The supply of SFH only goes down outside of distant suburbs as they are slowly replaced with commercial and multifamily.
2. Income inequality continues to grow, so the people with buying power will increasingly be people who prefer SFH.
Of course I am only talking about appreciation, and MF could appreciate less and still outperform because of better cash flow.
Some counter trends favoring MF are Asian buyers are growing in importance and care less about private yards than middle America transplants that historically fueled SD housing demand, as well as the trend toward older and smaller household size. This also favors two bedroom SF targeting small households.
A point favoring SFH is that you can resell to both a future owner occupant or fellow investor, but converting a MF complex to condos is a very expensive process that sometimes may not be permitted at all, so your resale market is only going to be investors.
