One of my more recent Eberron campaigns featured a pretty significant war between the more violent Druidic sects (the Ashbound and Children of Winter) and Thrane. My current campaign is trekking through the Eldeen Reaches right now, and I'm writing an adventure that largely takes place in Thelanis, the plane of the Fey.
Sharn gets a lot of play because it's such a unique and iconic city, and Eberron does set up a lot of hooks and seeds for "city adventures", but I sometimes feel like the "strong urban feel" is a little overstated. After all, the other two main iconic locations (the Mournland and Xen'drik) are a blasted magical wasteland and a literally unchartable, untameable wilderness continent, respectively.
Contributing to this is the fact that there aren't a bunch of really powerful canonical NPCs who can swoop in and solve every problem if they weren't too busy to do it because reasons. In 3.5 parlance, at least, a lot of the major high-level NPCs had mostly levels in NPC classes, so they weren't actually all that powerful. The setting's two most powerful non-evil NPCs are a preteen cleric that immediately loses nearly all of her power once she steps outside of her church, and a great druid that also happens to be a tree.
