Matt-
It depends on your goals, time horizon and individual circumstances.
For example, if you are 20+ years from retirement thats one thing. If you are interested in income that’s another. If you are above income levels where you can deduct losses against regular income that’s another factor. If you are buying a property to lock in for potential future downsizing that’s another factor.
What are you trying to accomplish (maximum gain overall 20 years, reducing taxes, maximizing cash flow, minimizing risk) ?
Personally, if you are in the accumulation stage (early -mid career) I think its optimal to aim to achieve zero after -tax cash cash flow. This allows you to put the minimum down, minimize impact to your lifestyle and maximize long term return.
Put enough down to allow your tenant to buy your property.
