I have been using Entourage for a while. I made the move to mail/adress book/cal a while back, when iSynch arrived. I actually like it. Especially mail. But, I had to go back. My main reason for using Entourage, besides it's great functionality, was it's super easy and perfect synch with my Palm OS devices. Always works. Apple's Adress Book's fields don't all match up, and has no real customization as far as catagories, and stuff like that. Other things really stunk about it too (in my opinion). Doesn't match up to Entourage, and maybe other apps. iCal, well, that screwed everything up. Duplicates, and all sorts of a mess. Maybe it's fixed now, but I don't know. Again, I think Ent outdoes it.So, Mail is the only iLike. Why use Entourage for everything but mail. It works just as well as Mail, maybe better, maybe the same. Mail looks better in my opinion. I like the paper airplane. But, that's not enough. So, that's my tale of not using the Apple products. I'm sure, once it's all equal, I'll give Apple another shot.
By the way, not to knock Eudora, I used to use it prior to Entourage's release. Loved it. But Ent does all that you mentioned above, and I prefer it. At the time Ent seemd to blow it away. It may have caught up. Don't know.