I had just discovered this app today while searching for Win Mobile 6 sync software for my macbook running OSX 10.5. I have an AT&T Tilt (HTC TytnII) that was immediately discovered and had the client connector software installed. My syncs for my selections happened without a hitch and was prompted for any changes to be made.
My favorite features from the Syncmate Expert so far have been the iCal, iTunes and the SMS manager.
Features I would like to see implemented would be synching of mail with Thunderbird since I do not use Mac's mail app. The integration with Google contacts, calendar and Firefox is outstanding.
I've had nothing but a great experience using this program that has helped relieve my frustration with Mac to Windows Mobile communications.
The UI of the app has been well thought out as well.
Color me a happy customer my two devices living in harmony.