Meaning (unless i count wrong) that if they still are in Act 1 at level 8 ...
What was discussed a while ago by community is also a possibility of a soft level cap per chapter. If we will have 12 lvls and 3 chapters a chapter 1: 1-6, chapter 2:7-10, chapter 3:11-12 would seem about right to me.
And of course, how fast we level in EA might not be representative of the final product.
