They are always the first to depreciate when the market takes a dip, they are always the last to appreciate when the market rises, and there are so many factors outside of your control from a value standpoint. 

We decided to start a Hardmoney company as I had owning one in SF Bay Area before . and since we did not need outside investors it was fine since we controlled it.

I had control over my agent but not the sellers agent.  

If it will make you insane to not be in control of your property (to the degree most would label the control factors), then don't do it.

Just got to find under-priced good ones.After the first time around, you will owe about $450k, but you will control property worth $600k = net $150k; an increase of 50% equity!

The funds are in the bank and I have checkbook control.  

I have a client that owns six investment properties, that is himself a renter.He lives in a rent controlled apartment in San Francisco, and has lived there for about 15 years.

Because of professions, much like yours, Airbnb has become a big player in the short term rental market.

., max. number of occupants, certain properties may also have rent control.    

Just a thought, but is there any reason you're not focusing on the more natural transition to controlling commercial real estate as opposed to going into flips?