This is all going to depend on the lease agreement you sign.  

Like Emily said, a number of shocking facts (or not so shocking to many landlords) have come out in the press recently on how few Americans can come up with a thousand or even four hundred dollar in an emergency....A FINRA study on The Financial Fragility of Renters was just one (with lots of stats).So no downpayment is a big one, as is credit score, and even with those who have resources, they  may want the flexibility to move or freedom from extra work or costs of maintaining and repairing the home.Even items like student loan debt or fear about the economy hold others back (still some out there who feel the sting of the housing bust).

The information being provided in smart move is the same information that can be obtained from any standard credit report.Past addresses… Credit scores… account information, etc.The criminal background check is public information.

Part of the answer depends on your ability to manage it well.

Also depends on what type of investing you want to do...a HELOC would be good for fix and flip, but maybe not so for buy and hold.

If your retirement utterly depends on having adequate cash flow from your properties, any downturns will cripple you.

i guess it depends on your strategy.  

So I guess it depends on what your budget allows.  

Does it depend on the property?

I approached a hard money lender - but again - my score is too low.