Its early I haven't had coffee yet so bear with me as I try and make this far more complicated than it is...
There is more than just a twist rate change there is also a chamber/cartridge upgrade called 6.8SPC spec 11 this developement on the chamber is much like the difference betwen a 223 and 5.56 chamber = basically a longer throat that reduces pressures by as miuch as 2000 or more PSI and increases velocities.
The change over to the 1-11" twist rifling also helps in lowering pressures as well the lighter 270 cal bullets that are fired in the 6.8 stabilize better resulting in better accuracy.
So if you have a barrel that is marked 1-10 it has the original 1-10" twist rate barrels and the older Rem saami spec 6.8SPC chamber.
If you have a 1-11 twist barrel you have the new updated spec 11 chamber.
There are reamers available that will allow a 1-10" twist barrel to be upgraded to the spec 11 chamber.
There is one more issue just like 223/5.56 you can shoot a 223 in a rifle that is chambered for 5.56 but you shouldn't shoot a 5.56 same goes with the 6.8 you can shoot 6.8SPC in a spec 11 chamber but you should shoot spec 11 bullets in a saami spec 1-10 barrel.
Hope that helps a bit.