I am using Visual Mill, still on version 4, but it is working well for me. I have a 3 axis wood working router and I am making musical instruments. I use Visual mill in the 4-axis mode and rotate my stock 180 degrees down the y axis by hand.

I have not figured out how to use regions yet (I have not tried too hard) as I think I have fallin into the pattern of learning enough to do what I need to, then not going any further. I create my tool paths, then use the tool path editor to clean up the tool path to fine tune my job. I really like the simulator.

Greg