Was running Mach 3 ver0.062, Smoothstepper and Gecko 540. Got tired of constant Mach 3 issues, unfixable bugs, lousy CV control and unpredictability. Mach 4 is no better and $200 for a half developed product and no customer support. Went with UCCNC software, 400ETH Ethernet and Gecko 540. Easy setup, stable and works great. CV control is light years ahead of Mach 3 or 4. VistaCNC pendant just released a plug-in for UCCNC so I can use my pendant now. UCCNC customer support is great. When I bought the 400ETH... UCCNC had a special offered for free software license.
Just finished a custom screenset that eliminated axis A, B, C and other functions I don't need. Added a simple Z zero and tool auto zero macro and buttons. Walked away from Mach 3 and never looked back.