I am using Poppler, Modi, and now Winrt.
I combine everything to make it nearly perfect.
Poppler to convert PDF to JPG (and previously also to Text)
Winrt (now) to extract the text.
both combined to detect blank pages and Poppler again to merge PDF to make a new PDF without blank pages
Then Modi to display JPG files and based on templates I create with Modi, to detect areas where are data to be extracterd.
I use the extracted text to determine which template should be used (based on VAT, account number etc...)

It is not so bad at all, I can do OCR on 90% of document

With the extration with the coordonates, I could probably be more accurate.

I also have another OCR, which uses an IA engine, and there, also I can reach 95% of accuracy.
But it costs arround 0.20 € per page