It is very usable, provided you pay attention to major upcoming changes. To give you a very recent example, during May they switched the time libraries to use 64 bits, and like others said, it was dependency hell until the tide of all the packages being recompiled passed. In those cases, unless you know EXACTLY what to do, it's better to wait for updates to come in, let apt sort out what could be updated and what had to wait, and just make sure it doesn't propose you to delete things. After 2 weeks it was all business as usual. Side note: aptitude (my package manager of choice) was unusable, while apt threaded on and pulled me out of the tangle.