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

I think it also depends on where you live - in places like New York and increasingly the Seattle area, the monthly payment is about the same or less to buy (if you have at least a 10% down payment and depending on the price of the home) and you get so much more for your money.Having a home is a bigger responsibility but owning typically far outweighs renting almost anywhere in the country.

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.  

Tax lien laws vary tremendously from state to state.

So I guess it depends on what your budget allows.  

Does it depend on the property?

You should be able to clean some of it up in months, not years, though it may be tough getting up to the 680 range, depending what your credit profile looks like over all.My investing group's credit expert is one of the top people in the country.