Robo financial advising - stock picking via machines - just took a big step into serious legitimacy with the debut of Betterment's Tax-Coordinated Portfolio tool.

A key tactic of human financial advisors has been to use asset location of investments to increase a portfolio's after-tax returns. It can make a big difference in terms of the money in your pocket. The calculation of robo-advisor Betterment is that asset location can lift after-tax returns by 0.48% per year which, said Betterment, can put an extra 15% in your pocket over 30 years. "Reducing taxes adds a ton of value to investors," said Boris Khentov, vice president of operations and a tax attorney at Betterment.

Human financial advisors have done exactly this for many years for their well-heeled clients.

Now, said Stein, machines can do this just as well. He added that New York-based Betterment is the only robo-advisor with an automated location tool. "It took us a year to build this," said Khentov. "Nobody has anything like it."

At least some human advisors snort at the idea of machine determined asset location. Their belief is that it takes a human's deft touch to master the intricacies. So it's war on.

Over exactly what? Put simply, in asset location, assets that are taxed more are tucked into tax advantaged accounts - think IRAs - whereas assets that are taxed less go into taxable accounts. It sounds simple. It is anything but. It is in fact an elaborate ballet. The location also needs continued updating. That puts it out of the league of many individual investors. "It's pretty hard to do," said Khentov, who elaborated that it's a "mathematical problem" - but it's one with multiple variables. "The tough part is figuring out what goes where," he added. "It's an optimization problem."

Worse: Small investors too often have not not had access to the asset location skills of financial advisors who, typically, are primarily interested in clients with substantial - think $1 million or more -- investable assets. That means the rest of us - the 99% - have been left out in the cold in asset location.

Enter the machine which, when programmed, can take over these chores and continually update locations as needed, claims Betterment. The price? At Betterment, the Tax-Coordinated Portfolio tool now comes built into every account.

Here's the money question: can a machine do asset location as well as a human? The human advisors - not unexpectedly - are skeptical.

"Finding an appropriate assets location depends on your risk tolerances and risk returns which even though you choose them on a piece of paper, it does not take into account the emotional feelings an investor may have based on market conditions," said William Connington III, a wealth advisor in Paramus, N.J. "A proper location is one that you can sleep with at night. I find the best locations are tasks best left to individuals and financial professionals."

Divam Mehta, a certified financial planner in Glen Allen, Va., shoveled more skepticism. "The task of a proper asset location is definitely best left for humans," Mehta said. "I emphasize with my clients that it is better to work with an advisor than to depend on an algorithm because the advisor has in-depth knowledge of the client's family structure, expectations, and requirements."

Ben Doty, a senior investment director with Koss-Olinger Financial Group in Florida, offered a nuanced view that sees some value in the work of machines - but not as a complete solution. "I don't believe determining the long-term asset location should be done by a computer or questionnaire because it's as much art as science to work with someone toward an asset location that reflects their tolerance for risk," he said. "That said, once the asset location is set, a computer program can put you into a decent model of assets and, more important, rebalance your account at a low cost. They can't do the work of making a call on the market, but computers can rebalance your portfolio back to a specific range, say, for equities. They can't, however, provide the same psychological benefit of an advisor during times of market stress or enthusiasm."

Add up the human skepticism and it distills down to this: asset location is an art, not pure science, and it can't be effectively done without sensitively dialing into this individual investor's needs. And no machine can do that.

So they say.

True? False? It's too soon to call the answer but know this: it's game on with robo-advising, as now the proponents are claiming dramatic gains in expertise. Will the machines deliver enough to woo some clients from traditional advisers? Stay tuned, because the fight just started.