I took a project and did the same process, coming up with similar results. The Revit schedule contained 2012 panels whereas Dynamo returned 2103 panels. The solution here is to only get elements visible in the active view. The Springs package has a node which allows you to do this called Springs.Collector.ElementsInView.
I don’t know the root cause for Revit and Dynamo to return different element counts, but I did notice that all of the elements which are present in Dynamo which are not present in the Revit schedule have no dimensions.
Valid curtain panel (present in Dynamo and Schedule):
The invalid curtain panel is a valid element (as you can see you were able to select it). These 0 unit x 0 unit panels are usually created when a curtain grid is excluded. What we thing happens is the ‘second’ panel is deleted, and a new, larger panel is created. What actually happens is one of the two panels is replaced with an empty system panel with 0 dimensions in all directions, and the second panel is resized to fill the void. Here’s a link showing it in action: Screencast Title
Knowing this, you can quickly filter these out by excluding the panels where the area parameter is not greater than 0 with a List.FilterByBoolMask node.