Without ever having used Preview on OS X or knowing exactly what output you're getting, it's hard to say. If you're mainly just getting rid of the whitespace borders, there are lots of programs that do that, including Acrobat itself of course.
For something quick and free, try
SoPDF (which is PDF > PDF despite being in the LRF forum for some reason)-- in addition to the core files posted up front, there's a GUI I made on page 2 of the thread. PageCrop, from one of the sticky threads in this forum, could probably do what you want too.
For scanned stuff, on the Sony, I tend to convert the PDF to LRF with
PDFLRF, which works just fine.
Rasterfarian might be worth a look too.