Have you tried backports? https://help.ubuntu.com/community/UbuntuBackports
PPAs are a very good idea but they are almost always managed by third parties and I don't trust them.
Also, upgrading the system every six months is annoying and fails too often. A rolling release decreases the friction of doing a major upgrade.
I've had really good luck with the last few major dist upgrades, for whatever that's worth. About half an hour of downloading and installing packages, a reboot, and poof, you're on the next major release.