Theory Question: 10% down, cash flow neutral after all expenses

[Scott Cooper]

Hi BiggerPockets,

Rental yields in my area are low.  To bolster the yields I would need to buy in areas that I would not feel safe managing the properties.  

Instead, in conjunction with a partner, we have been considering buying a number of rentals in good quality neighbourhoods where there is significant demand for rental properties.  The monthly cash flow available after tax, vacancies, capex,  mortgage etc. would be close to zero.

However, if we took the long view on such properties, with the aim to have them cash flowing well in 20 years after the mortgage is paid off, is it still a good investment?  From a long term wealth creation perspective, is there anything wrong with this approach?

Thanks