Every now and then they standard update with sudo pacman -Suy will break some hardware config or package combination. Often the terminal will warn you about changed packages and dependencies, but you should check the RSS feed or website for breaking changes.
Anyone with web search and some basic cli knowhow should be able to recover things in a short period of time, but I deliberately won't update just before anything that is time critical.
It will also happily let you break dependencies, install questionable packages from the AUR, and let you do whatever stupid crap you want. I would describe it as easy to customise, easy to break and easy to fix.