I've just hit level 12 with my party, and I'm guessing I still have a reasonable amount of act 3 to complete. I do agree that it's more fun when we still have character growth ahead of us, though also that new equipment can help keep things interesting up to the end game.
And what I really don't want is any more incentive to XP farm which more levels would introduce. In this first playthrough I've been pretty thorough, but I'd also want to be able to do a less completionist playthrough with a different character who would be more focused on the main quest, and still have them appropriately balanced for the end game and not feel I'm being penalised by lack of progression for roleplaying.
In short, thus far I'm feeling that the XP rewards are balanced pretty well, but let's see if I still feel that way once I've completed the game without any more levelling up!
