I've used apt-get for years, and never had a problem with it. That includes running with unstable, though the only unstable i've used is debian sid.
apt-get update + apt-get upgrade is your best friend, you should definitely not be scared of it.
dist-upgrade is of no use though, until there actually is a new distribution out there ;)

root@box>apt-get remove libc6
root@box>Yes do as I say
:P
Thats powerfull. (But dont try it)

apt-get has broken perfectly fine installs on my system (Debian Woody, Sarge). I mean, sure, use it for when downloading single programs to get all dependencies but - beware the system upgrade.