Debian

What I found does not work great, is mix all the different channels and pull in something big like an entire desktop environment. It's possible. But it'll require manual work and occasional fixing once it breaks. Switching channels entirely seems better to me, I've ran machines on testing or unstable before. And while it's not recommended to do it, it does work just fine. Just be aware of the consequences. And mixing stuff works if it's just one or two specific packages, like the latest kernel.