We found Apps4Pro to be extremely easy to use and although we encountered some errors during test migrations, working with JiJi support, who were extremely good and very responsive, we quickly resolved the issues and were able to complete the migration with the minimum of fuss.
I would recommend you trial Apps4Pro targeting a small set of simple plans to start with, and then build up to the more complex plans as you get more comfortable with the tool. You will probably have to revert to JiJi support along the way, but as I said earlier, I found them to be very good and very responsive whenever we had issues.
Good luck with your migration!.