Content-wise, what currently exists is all that will ever exist in early access. It's overwhelmingly unlikely that early access saves will be compatible with the final release.
This is not true. They have already said that they will add more content to EA later. Why wouldn’t they? That defeats the point of EA. They want feedback.
Why would they add more content to Act 1 and where would they add it? Every nook and cranny of the map is filled with quests already, you could probably get close to level 6 if we weren't capped, and I imagine its an average of around 25-30 hours for full completion as it is.
Sure they will add in the other classes, maybe flesh out some quests that are currently bugged or missing (i found lots of 'Story' items that seem to have no purpose...could be a later act thing like golden pantaloons tho) and they will probably give us level 5 to test the next tier of skills, but i imagine the flesh of the game will be after the 'starter island' DoS2 Fort Joy was only 10 hours of content if you walked.....they've tripled that here.
I know we all want more obviously, but I think it feels pretty damn good for a beginning act in this series. BG2's Chapter 2 was around the same length, maybe 5-10 hours longer if you did every quest imaginable, but you returned to that area with the chance to finish up anything you left out. We will not be returning to this area in BG3.
