The combo buys many more individual stocks than VT, although the extra stocks might have less impact on returns as the country allocation. The same goes for the expenses argument, which will pale in comparison to having 55% or more in international. Another consideration would be the foreign tax credit, which would be available if the accounts are in taxable.
The advantage of VT is that it avoids rebalancing and shifting allocations based on what's happening, such as selling more international because "everyone knows Europe is doomed" or buying more international because you believe China will rule the world and the stock markets. This is an easier way to avoid market noise and have a simple, truly market portfolio, without US bias. People on here have spent years obsessing over the perfect international allocation, which of course never was an issue in the 1990's, when the US was dominant, so by just buying a total world fund you can worry about more important Boglehead matters, such as where to find yield, will bonds tank, and how much to tip in restaurants.
If you want to find encouragement for holding the Total World index, read Charles Ellis in "The Elements of Investing", who puts all his stocks in the Total World ETF, or this article by John Norstad about why to invest in total markets: http://www.norstad.org/finance/total.html