The only reason I have one is that my company thinks we all should have one. But I sure don't love it. As a phone, it's okay, I guess. As a mobile e-mail system, it's very so-so, not due to RIMM's issues, but because of the way business e-mails are these days. I'd guess that 90% of my e-mails arrive with either a Word, PowerPoint or Excel document attached. A bunch of my personal e-mails arrive with a JPG attachment or 2. And, yes, I know you can open attachments with a Blackberry, but you have to really want to, and navigating around an Excel spreadsheet or a 30 page Word document is not a fun thing with a BB.
So for business e-mailings (at least the types of e-mails I get), I find the BB to be anything but ideal...unless your idea of a really useful e-mail is a title with the text body saying "See enclosed"