Stergios, for most users, there is no real difference between using one over the other. But you can install both and run side-by-side to test out your existing projects for problems. The only problems I discovered during my transition was that some add-ins that I used did not work without an upgrade to the add-in. One other area to look into is VBA or macro-heavy projects, which may break… but I did not run into that at all. Best!