I don't have a monogamous relationship with my device as I seem to change them fairly frequently :)
I'm hoping to pickup my Wizard next week... I loved the form factor of the JAM but could never quite get on with it as a Phone. I think the Wizard will be an excellent device because the interface with Windows Mobile 5 on that form factor will work so well - particularly the Soft Keys will make the device much better as a phone.
It'll be interesting to see if the additional girth the device has acquired (it's about 6mm thicker than the Jam) will prevent it from being pocketable?