Why Ubuntu? If you're not writing GUIs, Ubuntu is just a less-stable Debian.
PPAs.
Might be the worst solution but is the most well known.
Sure, it'd easy to set it up yourself. But the point is that PPAs are managed by someone else and have already been set up.
If I want a new software, and there's a PPA, I can just use that PPA and be able to use it straight away.