If you do a full restore then you'll have issues with the BES activation. That's what I've run into.
Start with a clean device and just activate it on the BES. All the user's previous info should sync from the server and the BB should end up configured just like the old one was with just about all the data. If there was 3rd party software that won't get sync'd.
There is always the switch device wizard for Desktop Manager. That will transfer everything over and then activate it on the BES.