In version 4 they have introduced new features that might be worth looking at ( depending on how you work). You now can rearrange pages on a PDF ; add new pages or delete; made a blank page to put in your own notes; rotate pages; email individual pages - quite a list of things to do with PDF files. There are also a few changes to lay out. For example the tool area can be hidden if you want.
You can upgrade the present version ( Version 3 ) to 3.21 at no cost. This update fixes a few bugs but doesn't introduce the new features. Or you can update to Version 4 which will cost you $3:79 at the moment. They are offering a reduction of 60% for people who upgrade in the next month.
I must admit - the more I use Goodreader, the more use I find for it - from annotating pdf's for study; file transfer and viewing unusual file formats.
If you are a person who uses Goodreader a fair bit a worthwhile upgrade.
Another aspect to Goodreader is "Goodreader USB". I'm not sure how useful this program is, seeing you can already transfer files directly from Goodreader on your ipad to any other computer, harddrive etc. But you have to set up the target computer to " allow " the transfer.
Maybe if you have blocked networks or some school situations this program might be useful. It transfers files to and from the ipad via USB. In case you hadn't realised the computer end of the ipad charging cord is a USB connector. You load a little utility on your computer and run it from there. How a look and see if it is of any use.