Just for the record: Arch does have testing and staging repositories for testing new versions of packages that may cause major breakage if they have bugs or packaging problems.
AFAIK new versions of glibc, other major libraries, systemd, Linux kernels, etc. are always kept in one of these testing repositories for a while to catch serious problems.
To help make Arch better, consider running one or more systems on [testing] (a chroot or VM will do) and reporting any problems you find.
Yes, both Arch and Gentoo are rock solid IMHO, and I enjoyed many years in both those communities. Breakage was very rare, less than one per year even, and I always ran test releases for my desktops.
AFAIK new versions of glibc, other major libraries, systemd, Linux kernels, etc. are always kept in one of these testing repositories for a while to catch serious problems.
To help make Arch better, consider running one or more systems on [testing] (a chroot or VM will do) and reporting any problems you find.