That CC3 drop shadow effect is going to get really popular! It does make maps look gorgeous.

Have you tried making a clearing in the forest around the lakes and rivers and applying the drop shadow effect? Not sure if that would improve the map or make it unnecessarily fiddly.

The only other suggestion I have is to consider making the width of the river larger from the confluence of the two tributaries.

Otherwise I have no suggestions only praise.

Ravs