First of all, for full disclosure, I have a lot of my retirement locked up in traditional mutual funds, though I've been working on increasingly building the flexibility (and often cost advantages) of ETFs into my portfolio. Fortunately, I'm not stuck in a crappy 401(k) account, so I can actually do that.

Unbelievable that the prices continue to come down on that portfolio—look at Vanguard going to 25 bps on emerging markets!  Overall, that's a pretty solid-looking portfolio, and I actually do own some of those funds.

But your asset allocation (which presumably is set up with yourself, i.e., long-term investment horizon, relatively high tolerance for risk, etc., doesn't exactly match mine. What is true for both of us—and it has put us both out of step with conventional wisdom until the outsized recent returns, perhaps, is our strong relative tilt toward international.

I'm very focused outside and still have more U.S. than I might like, mainly because of the (until recently) frustrating array of international size and style options.

And size and style is mainly where your portfolio comes up short.  I have always been one to think that it is completely legit to tilt your portfolio long term so that the allocation of your equity portion matches your risk tolerance the same way you do that with fixed/equity. This is one of the few areas where I've always disagreed with John Bogle.

I think that total market U.S. for most people will put them in WAY better stead than where they are, but for me, someone who is aware of what I'm doing and has a very calculated strategy, it just does not get it done. Do I OWN that fund (VTI/VTSMX/VTSAX)? Yes, as a very core part of my portfolio. But I also own (and I realize that THIS goes against John Bogle's original idea of style that younger investors would tilt toward growth and older investors would tilt toward more safe value) additional assets in value and in small-cap.  I just think you get more diversification (not to mention return) bang for your buck in those areas and the data supports me.

The other issue with Matt's portfolio, is I'm not sure if I'm sold on commodities, though I do like them (energy, gold) as a stabilizer or borderline macro-economic statement. Real estate I've never been a convert for. Heck, half of my real assets are invested in real estate. Why do I need another 5%?

So I love the portfolio, but I might add more EM (in the form of focused Asian exposure—WisdomTree, SSgA and PowerShares all have nice options), would definitely add some size and style, ideally including abroad, where SSgA and WisdomTree, for example, as well as iShares, have some options.

I know this feels a bit like an Arnott portfolio. And I suppose it is. But I'd stay with the 20 bps portfolio and tilt using cap weighting and not give up the 70 bps. That's my view. Maybe in 20 years the data will prove me wrong. But asset class exposure, minimum turnover and minimum expense are the things I know and can control and do.