I invest in rental properties personally and for my clients. Your concern about “worth the headache” is really the risk / reward question that needs to be answered for any investment opportunity. The headache is managing the risk associated with trying to realize the reward for investing.
An investment is “worth” the total return on the initial investment. While holding the investment, the return may be cash flow, dividends or “coupon” payments (from real estate, stocks and bonds, respectively). Once the investment is liquidated (for a profit or loss) the total return can be determined. With a rental property the net cash flow may be positive or negative during ownership and is the primary consideration for determining worth. If the property provides reasonable net income, the liquidation value should take care of itself.