I've been using pocket PC for some time (almost a year) and it's the most "interesting" application on my iBook. While it does work most of the time I find that it crashes regularly and that some features just don't work the way i expected.
I've posted on this recently at my site (
www.thepdaguy.com) as has Jenneth (
www.jenneth.info). Neither of us has had much luck with email sync.
Missing Sync doesn't support Entourage but it will soon. There's a new release coming and it will have support for Entourage. I'm going to buy Missing Sync as I've ditched Entourage and am using mail.app, iCal and Address Book.
I'll be posting on it in the next week or two.