Imagine you have several PDF documents that you want to merge into one big one. Usually, there's no easy way of doing so with Adobe Reader.
PDFMergeX on the other hand makes it extremely easy. It allows you to combine, transform and reorder PDF documents in little more than a few clicks. Using it is simple. Just browse to the PDF documents that you want to merge, order them in the sequence that you want to join them and finally click on the 'Combine' button to join them. PDFMergeX asks you where you'd like to save the final document and takes little more than a few seconds to process them.
If you're looking for anything beyond this, you'll be disappointed, however, because PDFMergeX doesn't come with any extra features or even preferences. You can, though, preview PDF pages that you've loaded and move pages into the order that you'd like to see them.
Although some users have complained of instability issues and crashes when previewing, I experienced no such problems. Just be careful when saving files to the same directory as the original documents, because it doesn't warn you if you're overwriting the original PDF with the newly merged one!
PDFMergeX is a simple and effective application that merges PDFs very well but not much more.