More available units would leave owners scrambling to avoid vacancy and forcing the market to support marginalized groups. 

This allowed me to get my money out sooner but I also held back some of the proceeds to use as reserves to absorb the vacancy costs.

I m on the West Coast as well and the dreadful Chicago winters would appear to be a challenge in terms of property management and maintenance as well as vacancy rates

It is far more valuable to spend a little more on something in better condition in a better area which will lower your vacancy rate, your turn costs for re-renting property and your headaches. 

It would be silly to say that a SFH rents for $2000 per month, therefore needs $200 allocation, but same structure across town with rents of $4000 per month, needs $400 allocation.Having said that, I wanted to know, for those with investing in SoCal, how much do you estimate vacancy, maintenance, and CapEx?

Our goal is to decrease vacancy time and self-showing technology eliminates the back and forth of scheduling which has proven to get more prospective tenants in the door and rent the units faster. 

As mentioned above, winter is usually a slow time for filling vacancies.

Does your cash flow include maint, CapEx, vacancy costs?

Try re-calculating with 10% each for vacancy, capex, repairs, and management. 

3% vacancy seems a little low to me