Is the ppa of LibreOffice to be considered safe for the system?

I've got some info on the website of Webup8 for adding a ppa from Libreoffice to the system (11.04) in order to get the latest, more stable version, of LibreOffice.

I've done that, and I'm pleased with the outcome. But I gave this as a tip on the Dutch Forum, and they received it as highly dangerous and risky.

I stay within logics: a new version (read an updated version) of LibreOffice (3.3.3) can't be so unstable that Ubuntu (the OS itself) will crash or do some strange things. (?)

I compare it with Windows: there you have the same issue with upgrading/ updating LibreOffice regardless what it can do with Windows itself. Or am I wrong with this comparison?

I see that it is for people whom use the office package professionally, as a more reliable way for getting a more stable version of Liberoffice.

How is your point of view for this matter?

In this case you can see that the uploads to this PPA are done by Björn Michaelsen, who is also the maintainer of LibreOffice in Ubuntu itself, which means it's not just some random guy uploading packages, you know it's someone who probably knows what they're doing.

Personally I feel safe using this PPA, it's used by a bunch of people and I haven't had problems with it so far.

However it is labeled as "test builds and backports", so I would use it for my own personal gear, but I wouldn't deploy it in production if I had to support desktop machines or if I was installing Ubuntu for a new user as even experienced developers can make mistakes in a PPA and probably doesn't get as much testing/exposure as the released version.

The LibreOffice PPA falls into the category of safe. It is provided by an official source, and it is only updated when a new stable release comes to the table. As The Evil Phoenix pointed out, PPAs are a case of "own risk", so you should still be careful with other PPAs especially, and careful with this one that it does not break any packages by being out of sync with something (as can happen when using newer software on systems that have not been updated to match the software).

Long story short though, this PPA is safe for use on a stable system.

No PPA can be confirmed 100% safe for use or not. PPAs are a use-at-your-own-risk solution, but most times they're generally safe (but there could be other system issues on your end that can cause PPA'd software to break).