@Chris Mendoza
Realistically you don't need cash-flow if you are making sure to hold enough for vacancy's, repairs, capital expenditures, taxes, and property management. But man is it nice to take home an extra 100,200,300 a month on top of what you pay yourself for property management.
As far as I am concerned in my own analysis of properties if I can't cash-flow $100 a unit in my market its just not a safe enough investment. Sure you are saving X amount for certain expenses but if you get hit with 3-4 big replacements in a year and you are already not making any excess cash-flow you are going to be paying out of your other income streams. On top of that you are not saving any money for new investments. I consider my property management savings my money and my cash flow as a stream for future investments.
I also don't like the idea of betting on appreciation. I consider it as a happy accident if the value does increase outside of forced appreciation.