Im honestly not sure about that yet. My highest character is like 42. I know all the dungeons and stuff are repeatable and resetable. and i like the more "open world" feel of it.

The level sync works great. lets you do everything at your own pace. one of my characters is in the 30s and hasnt started the 2nd act quests yet. my other one was almost at act 3 quests at 35. And your friends of any level can just hop in and they are at the same story quests, so no remaking characters just to play with friends.