Adobe introduced the PDF format to the world via Adobe Reader and although there are many competitors now, it's still the reference point for most PDF reading software.
However, its development from simple reader to bloated PDF tool hasn't been without drawbacks. One result is that it is now so overloaded with plugins and extensions that it's frequently criticized as being bloated and slow. Adobe have tried to address many of these speed issues and the memory footprint has been improved although there's no doubt that many users, especially on older Macs, will find it too slow still.
Of course, the main job of Adobe Reader is to open PDF documents which it eventually does. When opened however, Adobe Reader is probably the best tool out there for allowing you to navigate pages either manually or via search terms. The amount of preferences is absolutely mind boggling - Adobe Reader certainly can't be criticized for lack of customization options - and you can now upload files for sharing instantly at Acrobat.com.
However, for some reason there are many issues with 64-bit machines. One of them is that the PDF viewer plug-in is not compatible with Safari running in 64-bit mode. Another problem is that it does tend to mess-up fonts in Word documents that have been converted to PDF when opening them.
Adobe Reader is one of those applications that started off well but now has many enemies, especially on Mac. However, it's still a decent tool if all you want to do is view PDFs and don't mind hanging around for them to open.
- Latest release. This is a regular quarterly update that provides security mitigations, feature enhancements, and bug fixes