More Examples for the sake of the thread.
You can also use SQL Functions, Ice SQL Functions.
Behind The Scenes
SearchFilter + EpiFilters + EpiFiltersAppend are just combined and executed against SQL (they are not post-filters).
Also just for the record, if your SearchFilter starts with CodeTypeID Epicor will set the DropDownStyle Automatically to DropDownList. So you dont have to set it in Code anymore.