As of October 17th 2011 Adobe now support their mobile reader, Acrobat X for IOS. I have the app on both my iPad and iPhone and find it just a little slow when zooming ie., (the image and text remain blurred for about 1-2 seconds ) compared to reading the same document in iBooks, no problem, pinch or zoom and the document remains clearly focused.
Negative comments on iTunes are a little misleading and relate generally to functionality that this was not designed for nor what the full reader was designed for. Remember this is a document reading app.
However, I found that the file manager could not identify all pdf documents stored on my mobile devices and some genuine complaints have been leveled at the AirPrint functionality. AirPrint on IOS could not recognize any printers installed on a wireless network that I was using to test this. This was possibly an issue with IOS Bonjour protocol being disabled on this particular network..
R . E . W . I . R . E . D 