To be very honest with you, blackberry is really addictive. But it also depends on your needs. It's really great to be able to receive and send emails wirelessy on it. It could save so much times. Just for an exemple, normaly, I have to spend at least a good 2 hours to reply emails everyday (for work and personnal) but since day 1 I got my BB, I can reply anytime I want, in toilet doing business, or at dinner waiting for food, really any time.
As for notes, that's another reason why I can't live a day without a blackberry, school notes, personnal notes, task, etc. they are in my BB.
Then again, it really depends on your own needs.
kalok~