Some aspects of it are too spread out, some aspects are too compact. Those hilly wetlands Lollard mentioned are good example of something too compact. Actual wetlands (I live in Maryland which is known for its marshes and wetlands) are typically much flatter, so having hills of that size makes it feel squished together. I've also had the experience where they can make up a significant amount of terrain (without changing worldgen settings).
Currently I play with a few worldgen mods, but I'd love to play the game without them, or either way have it improve significantly. I always set land cover to between 40% and 70%, regardless of mods. It feels super excessive at 97.5%. Since rivers are presumably coming in a future update, I'd imagine (and hope) that'd be an overall world generation update. The worldgen by default right now just seems too variable, especially in heigh in areas that should be flatter.
