pacman, seriously, I don't hear enough of how great pacman is.
Being able to search easily for files within a package is a godsend when some app refuses to work giving you an error message
"lib_obscure.so.1 cannot be found".
I haven't had such issues in a long time, but when I do, I don't have to worry about doing a ten hour search, if I'm lucky, for where this obscure library file is supposed to be located and in what package it should be part of.
rolling release. Non-rolling Ubuntu half-year releases have broken my OS in the past around 33% of the time. And lots of apps in the past had essential updates I needed, but required me to wait 5 months for the OS to catch up.
Hmm, finding what package a file is in is absolutely possible on Ubuntu/Debian too. You can use the online Ubuntu/Debian packages search, or use apt-file.