I don't use either. I put a KFlop on my Pro as soon as I got it, and I run a CNC controller application I wrote myself.
You should try both Mach3 and LinxuCNC. LinuxCNC has a reputation for being very stable, but it is also pretty minimalist in functionality, and the UI is very simple, and rather crude. It can be modified, but I never got deep enough into it to learn how - seemed like too much of a project. Plus I run other apps on the machine that are only available for Windows, so Linux was kind of a non-starter for me.
Bottom line, it comes down to personal preference.
Regards,
Ray L.