Since we bought our investment properties in San Diego many years ago, our cash flow and costs, etc., pencil out a lot differently from yours, so it makes a lot of sense for us to keep our rentals long term. We did, however, sell a couple of our properties at the last peak, because the timing was right.
IMO, and this is not advice, I don’t think you can go wrong holding onto investment property in San Diego. That said, given the volatility of the current economic climate, this would hold as long as you know you can afford to do so, even if there is another downturn in the real estate market, and, if you know you will not need the cash for any other of life’s many surprises.