Bit better than the free version of the program..

They both allow you to use the reader that comes with the program to listen to PDFs as audio (the voice isnt very good, and you cant adjust the audio speed), but its better to use either Apples VoiceOver function in the PDFs audio section (you need to read the page by sections, selecting one at a time) or SpeakSelection (its best to use this if you can, as you can select an entire PDF page to read out once in the PDFs audio section) in terms of the voices sound and options. At least this program has VoiceOver/SpeakSelect for PDFs, which iBooks currently doesnt. The biggest advantage of the paid version is that the free version has trouble saving bookmarks which can be a pain with longer books, the paid version reads text much more smoothly, and you can adjust the text. My biggest qualm is that in the product description theres a quote about it being stable with multitasking - but in the paid version as with the free version it doesnt allow multitasking while its reading text to audio (the primary benefit of this app over other PDF readers Ive used), if it kept reading while multitasking Id give it 5 stars.
Update: Version 2 doesnt have the main thing I used this program for - audio. I can still use VoiceOver with this version so its not a complete loss, but I cant use SpeakSelection. Updating caused me to lose my existing bookmarks (luckily there werent many as I was reading short stories and keep track by writing the page numbers Im on in a text document just in case), and the page numbers at least for one document are a bit off from what shows in my other PDF readers (only by one page number so far, but still). Also I dont seem to be able to change the text/page format (there used to be Sepia, which was easier on the eyes in the dark than glaring white). Oh well, I can still use VoiceOver (its just a bit of a nuisance when the chapter Im on starts half or more of a page in - also its a bit hard to see the tiny PDF page text since it doesnt render the fornat of the page to be read, making it harder to follow along visually if need be) - still, I hope they update it with the improved program voice or at least the ability to use SpeakSelection with the text again.

Xyia about PerfectReader Pro - PDF & Document Reader for Adobe Acrobat & Microsoft Office, v2.0