Having carried a free CrackBerry for 2 years, I don't carry one today.
I don't have a problem shutting it off. But the CrackBerry makes for a HORRIBLE phone, especially without a headset. The volume is too low.
I'm also glad not to be tied to my email. But then again, even with my CrackBerry, I took my sweet time to answer emails that weren't urgent. Even urgent emails that weren't really urgent either were put to the bottom of the pile.