scott, I agree with you on several points, but not in your preference. While most of the things you say are true, I still prefer Outlook because it's simply nicer to deal with from GUI standpoint. Having features and being able to do things is one thing, but there's something to be said for having a nice interface to do it in. I remember writing a couple of rules for Groupwise that were a PITA simply because of the way I had to do it. The way everything is laid out in Outlook is much nicer to deal with than Groupwise.
It's funny, I'm normally a function over form kind of person (see all my rants about other software here at DC) but I just hate Groupwise. I never liked Outlook either until I had to use Groupwise. Everything about it was so ridiculously minimalist. I guess I don't mind minimalism for little programs--actually, I prefer it, you don't want a big bloated program just to rename files, or burn a cd, etc.--but your email and PIM is something you use 24/7, so the interface and layout is more important.
So, I can really do without the lack of a good message status feature, or a weirdly implemented addressbook (yes, this puzzled me also...very strange). As far as archives and searching, I don't use them on a constant basis so I can deal with that fine. Seriously, I'm so freakin happy to have Outlook. I never want to see Groupwise ever again, it's a piece of crap.
If only I could use the Bat! at work...however, it doesn't have the calendar features and stuff. Oh well, I'm very happy with Outlook.