Choosing which one is better depends on your financial circumstances, the property in which you’re investing, and more. Positive gearing essentially means the rental income is more than the expenses.
Negative gearing carries with it tax benefits, but means you will need to be able to cover the out-of-pocket expenses (i.e. losses) until tax time rolls around. Negatively geared investors also hope the capital gains made on the property outweigh the rental losses incurred. Capital gains, of course, aren’t guaranteed.
Having positive cash flow means you can generate profits straight away, build up a buffer in case tough times hit, and means you don’t need to be out of pocket for expenses. However, having positive cash flow means there will be capital gains tax payable on any positive income generated.