readdledocs is slow, unresponsive when rendering pictures and slow with PDFs as well. not to mention that it almost never gets updated.
I have to disagree with you. ReaddleDocs might be a bit slower on rendering pictures, but for files it might be even faster than GR (depending on file).
We produce update regularly to all our apps. Have a look at this: http://appshopper.com/business/readdledocs-for-ipad