I cashed out all my bay areas rentals about 2-4 years ago, near the peak. All the money has been invested in out of state markets at much better return and cash flow.
When stock market is breaking records in the last 2 years, but housing market has been flat or down in the bay area, it tells you something. Positive cash flow with 90% already pay off is not good investment strategy. 2 options:
1) refinance and get money out to invest in better cash flow areas
2) Sell and invest in better cash flow areas
Personally I prefer option 2) as I am not optimistic about the market in the near to mid term. Many friends in the bay area have told me their companies are starting to do major lay offs, from Cisco, to Stanford University, to non profit such as Girl Scout. Google just terminated 2000 contractors positions. Even more companies started hiring freeze and reducing contractors. This wave does not seems to focus on few companies or industries, but across many segments of the economy.
My wife and I are talking about selling our house in Palo Alto and rent for few years. We did that before, sold in 2007 and brought larger one in 2011 for lower price and made tremendous profit in both transactions. We still have not decided as my wife really likes our current home. This shows how optimistic I am about the market in the bay area