Hi Hilton -
One of the main reasons for it's popularity, is the ability to hand (or e-mail) a file created on your pc, and have it look EXACTLY as you planned on PC's, Unix, and Mac's. That includes, Fonts, colors, photos, sound, and video.
It is so well accepted that even my printer prefers acrobat files now.
I continue to read of all the various tools that some say are better than the other, but whether we like it or not, Acorbat has become a widely accepted standard, not only across platforms, but across industries.
It has security, and the latest update even ahs the ability (with a provider based tool) to "lock" a book you sell to an individual, an e-mail address, or even a specific hard drive.
BTW, the version shipped with Pagemaker is still not the complete Distiller, missing some of the capabilities shipped with the stand alone Acrobat. Like you, I also use Pagemaker. I bought the commercial version of Acrobat and love it.