@Joey has linked to a very nice post by @lupo:
Who in turn linked to a post by Taylor Larimore:
https://www.bogleheads.org/forum/viewtopic.php?t=88005#p1263932
To recap, avantages of VTI+VXUS vs VT:
- lower TER
- lower turnover
- deeper market penetration (some 2’000 stocks more)
- flexibity (ability to overweigh or underweigh USA)
You know, maybe in the end all these sum up to something like 0.2% difference. So for portfolios under 100k it’s just pennies. But for larger portfolios I would say it makes sense. It definitely makes more sense for Americans, because they are better off being able to overweigh USA.