I was just reading this really interesting article showing the perspective of an avid Windows Mobile users take on the BlackBerry. Adam Lein is one of the senior editors on PocketNow.com so his experience with the T-Mobile 8820 was a refreshing perspective on the difference.
I know I am a little biased but if you read the comments in the forum you can get a fresh perspective on the whole conversion process.
So have you used a Windows Mobile Device before?
How does it compare to your BlackBerry?
Personally I have tried multiple times to use a Windows Mobile device. This includes the Moto V9, BlackJack, Mogul, Touch, and many others. Personally I found the devices powerful but it always came down to one consideration. If you care about your email and PIM always working then there is no replacement for the BalckBerry. Yes it wont do video, yes it does not have as many applications, yes it is limited, but those are all perks to me and not a necessity.