"...Adobe Reader "Internet" preferences and uncheck the "Display PDF in browser using:" option." as per PeterWindle post earlier.... in https://fmdev.filemaker.com/message/83231#83231
This worked. Had to do the change, quit Acrobat, Quit Filemaker, go back into Filemaker and presto it's now using Preview...... yay....
You can also right click the toolbars to control them like in Acrobat proper.
Depends what you want to do with the PDF too. Preview on the Mac is a REALLY poor implementation of a PDF reader, as it ignores quite a few things in the ISO standard that defines PDFs. Acrobat is not perfect either as the chrome is way too dominant but there are lots of places where it shines.