I'm a fan of both operating systems, but I have had a much more pleasant having updated versions of packages by default in Arch than by heading over to testing

I'm a fan of both operating systems, but I have had a much more pleasant having updated versions of packages by default in Arch than by heading over to testing or unstable on Debian - in other words, the newer packages on Arch felt far more robust than the unstable packages on Debian. This leaves aside the fact that stable Debian was far more stable than Arch for me.