I use Arch for all my computers, including my "critical" systems. I only do full upgrades when I know I have the time to troubleshoot something broken, but rarely need to do so.
More than this, I actually use Arch as the OS for thousands of computers for my work that end up in customer hands, who expect stability. I'm not sure at what point it stops being Arch, though - I pin the package repositories to internal mirrors with fixed package distributions from specific dates to control the software that goes to them, so it's not really rolling release anymore I guess - I control the releases and when updates go out.
Arch is what you make of it. My Arch project desktop pc is constantly shifting and breaking and needing attention as I continually improve it and play with things. My Arch laptop that runs my life and work and is the most important computer I own is a paragon of stability and perfect functioning.