I have started discussions with a client about migrating them from CM/Unity 4.X to CUCM/Unity Connection 8.X. My plan is not to upgrade them from 4.X to 7.X to 8.X, but rather to migrate them from 4.X to 8.X by building a parallel VMware server along side the 4.X serevr and just re-enter the config parameters by hand into 8.X while looking at the 4.X screen. They have about 100 phones/users, so I think it would take less time this way than the stepped upgrade process.
My question is: could I use the BAT Export Data function on the 4.X and then use the BAT Import Data function on the 8.X and get most of my system and user configuration input that way? I assume that the database fileds are the same between versions even though the databases themselves are different.
Regarding Unity, I am not concerned about keeping any old voice mails messages. I would build the CUCM, then build the UC and import users from there.