Simply because partial upgrades are not supported, always do -Syu unless you know for sure nothing will break.

doing always presents one with a [Y/n]-dialog anyway.
and yes, i look at it before i press Enter (=yes).

i like archlinux a lot, i think it will remain one of my top favorites, however, as i expand into needs that go beyond just myself personally, setting up linux on other peoples computers, servers, both things that may require a bit more of a stable enivonment as well as some issues ive been having with steam and the catalyst drivers, ive been leaning towards going back to a distro that can offer me a more stable non-rolling type of release model for the distro i put on and manage for other people, plus as i place more interest in building a private server for services that serve the need of friends and family