The vote will lean towards Mach, purely because there are a lot more Windows users than there are Linux users. Ironically, a lot of people rave about how good Android is, little do they realise that it is a Linux based O.S.

Personally, I've been 100% Linux on all my PCs for a few years now and am very much a fan of open source projects. I've converted a lot of friends to Linux Mint and they love it. They often thank me for introducing them to it as they had never realised that Windows and Mac are not the ONLY operating systems available. But Linux isn't the answer to everything. Windows has better support for games and certain other programs. But they're mostly commercial software and I prefer FREE. The main bonus is that Linux doesn't suffer from all the instability and security issues that Windows seems to be renowned for. It's not surprising that most of the internet is run from Linux servers and one of the servers I rent in London hasn't been rebooted since I started using it in 2009!

Having said all that, most people don't like change, so stick with Windows purely because it's what they are used to.

As for LinuxCNC...dunno yet as I'm only just starting to use it. But I got my first ever stepper motor running within a couple of hours of reading, so I can't imagine me trying anything Windows based in the near future.