In my situation they make them acceptable investments and a good diversification. 

Account Closed I'm maxing out on the pre-tax contribution amount every year, my employer matches 5% of my pay contribution, the markets would have to have an average loss of -15% every year for the next 25 years for me to end up with a balance that consist of just my payroll contributions.I think those numbers on the charts you're listing are for people working low wage jobs and probably contributing a few hundred dollars a month to their 401K plans, in that scenario putting 200-300 dollars a month away is something that will help but probably not going to be enough to live on in retirement.Like many have mentioned on here you have to be diversified with Real Estate and various aspects of the financial markets, If you're heavily positioned in one market or the other with no diversification you'll end up in the average pool of investors.

Forbes has a habit of putting something like this out every few years.The "bad" thing about investing your IRA in real estate is that the main Wall Street players do not have control over your funds and the means to earn commissions selling financial instruments.His arguments are entirely tilted towards to negative and not providing any context or perspective.I could just as easily pick 3 or 4 historically bad stock investments (Enron) or high fee annuities, and make it sound like that was all that you could expect if you went to a conventional brokerage - which is clearly not the case.For someone who understands real estate as an asset class, there is the potential to have your IRA produce consistent returns and have true diversification away from the news-cycle volatility of conventional financial products.

@Ron Willbanks I've seen people do it for state of mind and also to partner with others so that they can each invest half of the minimum in double the number of deals (to increase diversification) but, as others have said, it's not necessary if the Sponsor structures efficiently.Unless you have a special circumstance, it's kind of a waste of money.

This may be interesting for some diversification. 

In all likely-hood you will loseYou can also take minimal risk and get very small returns like a CD paying 2%.The key is to find the sweet spot in the middle of those two with enough diversification to protect you from one bad decision.But back to your original question.

If you are not self-employed, then a self-directed IRA is a great option.Either way, the plan is all about diversification for retirement savings. 

Thanks to Jay Hinrichs I discovered the beauty of syndication deals for passive income, diversification, and heavy hitting returns.

3) Diversification is the way to go.

leverage is needed to scale.Although some diversification can be good as well.. he could buy a few rentals then buy a nice performing note that will not have the risk of tenants.. if a tenant should not pay one month he or she still has the note income.. also could use the note income to further snow ball that mortgage..