Not really, even if you didn't use any leverage at all you'd still get awful results. Leverage will help only if the rate you're borrowing at is lower than the rate of inflation over a long period of time. *edit, or of course if you time it right buy 2016 sell 2021 etc...
If you own rental property then have a look at your price to revenue and ask what margins you are going to achieve and compare to say Google or Apple.
If as per his example you have a million dollar property returning GROSS 800/w that's a Price to Sales of 24 times.
More expensive than just about any business in the world. Now even if your margins are higher than Apple and Google you're going to have a pretty awful result.
Berkshire Price to sales is less than 3 times.
A property returning 800/w with a 50% Net margin (impossibly high) is worth $260,000 if you want a 8% return. It's that simple.
In aggregate investors cannot earn more than the 800/w less all expenses as that is all the cash generated.