Mike, i dont doubt that you are correct about each group advocating their personal favorite. Over the years my company's changing standards have put me in the position of using a bb6750, bb7280 and now a treo 650. The blackberry is the best for email, period. While the costs of the devices are similar, my treo 650 needed additional software to work with our corporate mail servers. We already had a BB enterprise server so that cost wasnt an issue.
I will say that after some initial software problems with the treo 650 i do feel that its a pretty good phone. The form factor is managable in your hand. I never really liked the phone on the 7280.
However the overall package of the 8700c is appealing. Our B2B Cingular rep will be shipping me one to try out once they are in hand, probably around the 21st like everyone else. If the phone functions work as rumored I will likely switch back to using a blackberry. Bottom line is there is no one size fits all. I dont want a camera, and have no need for multimedia on my phone. If i want music I can use my ipod. So for me a blackberry is probably a better fit. But if you are a former palm user,or want more multimedia then maybe the treo is better for you.
I am just glab we now support both BB and Treo so I can choose my toy of choice!

--fc