1) Why upgrade to Adobe Acrobat XI?
There are many useful features like
- Create PDF from Office 2010 and Web Browser
- Conversion from PDF to excel,word,powerpoint
- Reorganize pages before merging into a single PDF
2) What are the differences between the Adobe Acrobat Reader, Standard and the Professional Edition?
Essentially, there are some the desirable features only found in the Standard and Professional Editions
- Create PDF
- Convert PDF
- Directly Editing on PDF
- Reorganization of pages in PDF
- Sign Document Electronically
- Protect and Restrict PDF
- Insert Audio/Video in PDF (only in Professional)
- Create Web Forms in PDF (only in Professional)
- Compare differences in 2 versions of a PDF (only in Professional)
3) How to upgrade from a Older Version of Adobe Acrobat
Basically, you can upgrade from version 8,9 and 10. Older version like 7 an earlier do not qualify for the upgrade.