I've been using Arch for two years before going back to Slackware. It was a good run, Arch is fun and easy to use and everything works very, very well. On the same laptop is even faster than Slackware (I did not run any test, it was just my perception after a fresh install... maybe because Arch has way less packages...).

BUT Arch brokes often. Even when I look the news on the official website or search the forums for issues with recent updates, even when I check that everything is ok accordin to the (awesome, really awesome) docs, Arch brokes something.

I grew reluctant to run "pacman -Syu". Now with Slackware I am 100% sure that my system will always work after every update, and if it doesn't work is because a simple new dependency that I can install in a couple of minutes if I want, or I simply keep the already installed package without any issues whatsoever.