Hi, that topic is very useful, please insert into main documentation of pdf.PdfDocument.ExtractText.
Using pdf.PdfDocument.ExtractText, formatted text and others returns dirty.
Using pdf.PdfLoadedDocument.ExtractText, all works fine.
Or still have (2017) a bug into pdf.PdfDocument.ExtractText comparing to out of pdf.PdfLoadedDocument.ExtractText.
Thanks!