Im pretty new to rianworld as well but i have played a bit with artificer which is a slugcat from downpour and from what i have seen so far is that there are a few changes to all aspects of the game with each other slugcat you play. so artificer for example may have an entire new map region that only he can access and would ever be able to find.
Though on the other hand, if you didnt like the game in general and only like exploring, it may not be entirely for you as there are also a lot of new mechanics that you are given.
but generally speaking, the whole game changes in little bits in all perspectives.