We were able to run the tool in our production environment this past weekend, and thought some of you might benefit from what we experienced.
Firstly, during the extract, we also ran into many users showing as non-existent. To rectify, we confirmed the time zones for each user (luckily, most of our users are in the Eastern Time Zone), then added them to the Mailboxes_x.txt with the correct time zone designations.
We have just over 1000 users, so we split the jobs up to run on 3 seperate servers with the tools installed. 2 servers were running version 2 of the Exchange tool, one ran the original (I found issues uninstalling the original on this server; instead, I kept the original). The TZMove was also the original release. Each server carried between 320-350 users.
When we ran, the V2 tool was finished in about 1-1/2 hours, while the original took over 2 hours. However, it did manage to only error on 21 users, most of which were service accounts.
We did testing and had users on conferrnce calls over the weekend and on the Monday following. All in all, we had a successfull run
Hope this helps