PDF Expert for Mac is now available on the Mac App Store for $19.99. As part of a limited time launch promotion, PDF Expert for iOS is now free on the App Store (down from $9.99).
When it’s time to edit, all the great tools you need are easy to find and just a click away. PDF Expert’s quick annotations, easy form filling, and powerful file merging will chew through your work in record time.
* Read – An award-winning, lightning-fast, and tabbed document viewer will get you through multiple PDFs faster than ever.
* Annotate – Classic tools and unique innovations enable you to highlight, note, and instruct with just a click.
* Edit – Easily make your mark by adding text, customized shapes, and more.
* Merge – Combine multiple documents into a new PDF, or borrow individual pages.
* Sign – Create multiple signatures for every situation and sign on the line with a single click.
* Fill Out – Avoid your printer with smart tools for filling forms that save you both paper and time.

I stopped using PDF Expert on my iPad because it only has folder sync option. iPad doesn’t have so much space so this doesn’t make sense. As oposite to this GoodReader allows single files sync and its packed with many other features that PDF expert is missing.
I forgot to say: and all that for half a price!
I don’t get the advantages over the build-in Preview application of OS X? Read, Annotate, Edit, Merge, Sign, Fill Out — that’s everything I was already able to do with Preview :)