Equal in size to one of the larger planets? So let me get this straight. You're calling this Chapter 4. Chapters are typically 3-5 planets INCLUDING these larger planets. BS. Complete BS.
Let's talk level content wise. Alright, Chapter 3 starts at Level 41, correct? If it ends at Level 50, that's 9 levels for a Chapter. With exp inflation, 5 levels for a chapter is reasonable. Remember, this planet is going to have to have enough quests to deal with that exp inflation. Size doesn't really matter. Amount of content? That's a different story. And judging from exp increases, we'll be getting plenty of content.