Investing in a C- area

[Seth Lind]

Many of the properties in my home market that appear to be good deals tend to be in an area I would consider "C-".  Far from inner-city but in the rougher area of town.  

My question for the experienced investors, what would be the downside to investing in these areas if I'm using a property manager?  I've heard investors recommend staying away from these types of properties, but if there is a property manager involved to use as a buffer from tenant issues, why not?  I understand my appreciation would be less than other areas, but if the numbers work to make it cash flow, appreciation isn't my focus.  I would be using a management company that does not charge for filling vacancies so turnover isn't a concern.  

The properties I've been keeping my eye on are staying available much longer than similar properties elsewhere so it appears other investors are staying away.  I'm afraid there must be something else I'm missing.

Thanks for your input.