That's some nice info. From what I've heard manjaro is just arch with things done for you most users would do anyway (Desktop environment setup, package management set up, etc.)
But if arch is more stable even if some casual hobby ITler like me installs it I should maybe give it another try at times.
Didn't know there was much difference between arch distros, but now that you mention it: steamOS is working flawlessly while being arch could be an argument for your point. It thought this was more because its perfectly configured for the hardware and deck and I seldom need the OS itself outside of steam because I only use it for gaming.