The only things I can see is a few minor gaps between rivers and their tributaries and the rivers and the coast. Beyond that, the coastline looks a little too regular for the distance. I would expect it would be more jagged or varied, with little bays, inlets, and islands on the coast. But that's just a personal opinion and I'm a bit of a realism freak.

Otherwise, it's really beautiful. I especially like the way you modeled the terrain. It feels like I'm looking at a satellite photo.