As long as you're using the current version of DM for Mac you should be okay. I did the same thing (Mac to Windows).
BEFORE YOU DO ANYTHING BACK-UP YOUR PHONE!
I can't stress this enough! You can do it on your Mac but your PC will be fine.
Things to be aware of:
1. Make sure you have no contacts in your address book on your mac before syncing. It will duplicate contacts. However, keep the ones that you don't have on your Blackberry.
2. As of right now I have contact picture issues. I use photos for all my contacts and when I upload them through address book on the mac, they appear very small on my blackberry. I've posed this question in a forum I started on DM for Mac issues (
http://forums.crackberry.com/f62/pos...issues-358565/) but haven't had any luck. If you use pictures and already have the appropriate sized ones on your Blackberry, then they won't be affected during the sync. It is only when you change it on your address book.
3. You will not be able to sync until you set up the sync options in the left sidebar. Be sure to select the right option. I do not like the limited options DM for Mac gives you.
4. You can't transfer backups saved from your PC to your Mac. They are different file types.
Desktop for Mac is much more user friendly and very simple. It's just plug and go right from the start!
Check out this link on Desktop Manager for Mac for everything you need to know:
BlackBerry 101: BlackBerry Desktop Manager for Mac | CrackBerry.com