Why to migrate? Here are the key reasons to use the new updated API provided by GroupDocs.Annotation for .NET since version 19.8:
The Annotator class introduced as a single entry point to manage the document annotating process to any supported file format (instead of AnnotationImageHandler class in previous versions). The overall Rendering speed improved dramatically by saving rendered page as soon as it was rendered, not when all pages list were rendered.... The overall rendering speed improved dramatically...by saving rendered page as soon as it was rendered, not when...