I'm pretty sure this guy is full of it.
There are some longer range issues with the 6.8, but it's not meant to be a 800 yard line drive tack driver.
1/10 twist only has issues with high pressure loads. It should stabalize most 6.8 rounds out there. (don't have a 6.8 yet, but just from reading reloading data, etc)
Edit: also I was under the impression that most rounds don't stabalize immediatly after leaving the barrel. Most bullets tend to settle down in flight. But you're not going to have the issue of 1/12 twist AR shooting heavy bullets where it doesn't stabalize the bullet.