When buying an investment property, is already rented out better?

[Jeff Howard]

When buying, say a duplex, is it better to buy one empty or already rented out? What are the pros and cons... I can think of a few...

Pro: Already rented

Conn: You have to follow the current lease agreement

Question: Will I be able to thuroughly inspect the property, i.e. behind the washer and dryer if there are renters in there?

What are some real pitfalls here?