I made the transition a little over a year ago and, amazingly, it comes close to a uniformly positive experience. I think it is the fact I can pop up a terminal and suddenly I'm in Unix-land that really makes it for me, but the software written specifically for the Mac tends to be quite good as well.

For that reason I suggest you *do not* go with the Mac versions of standard software (including, yes, both MS Office and Open Office). Instead use NeoOffice or one of the Mac only word processors. They map better to the GUI.

Have fun!