Investors & landlords

I'm mostly interested in short-term advantages at the routine micro level (I guess "present return on investment," as you refer to it, Opus, and I thank you for your response).  For instance, if I can deduct 20% of the expenses (my tax bracket), that deduction effectively increases my monthly profit, if my thinking is correct.  

So if I have $800 in expenses, I can tack on an additional profit of $160 to my monthly net income.  And this benefit wouldn't be common knowledge to the casual observer.  I'm wondering if there are other such advantages I'm not aware of.

I didn't know, Opus, my heirs would not have to pay capital gains or recapture depreciation.  That's good to know, but as I said, I plan to sell at some point in my lifetime.

What is the 25% of depreciation recapture? Does that mean if I got deductions amounting to $10,000 for depreciation for the whole time I owned the property, I would only have to pay back $2,500?  I thought we have to pay back the full $10,000 - no?

My ROI is less than the S&P average, but I'm thinking it could get closer if there are other advantages.