So , I let you decide which version you want to use and of course its all up to you.
Use it at you own risk.
Here is the PPA => LibreOffice - Pre-Releases for Alpha - Beta versions of Libreoffice.
The description from PPA
This ppa contains alpha and beta release (before the 3.X.0 release).
Only for the most brave and courageous!
The installation instructions from PPA
to test these do:
sudo apt-get purge libreoffice-core
sudo add-apt-repository ppa:libreoffice/libreoffice-prereleases
sudo apt-get update
sudo apt-get install libreoffice
The installation instructions from Webupd8.com
sudo add-apt-repository ppa:libreoffice/libreoffice-prereleases
sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install libreoffice-gtk3
Here is another PPA => LibreOffice Packaging Team
The description of PPA
LibreOffice test builds and backports
There is a PPA dedicated for the 3.5 series which supports
Lucid/10.04, Oneiric/11.10 and Precise/12.04 for a more stable
experience!
https://launchpad.net/~libreoffice/+archive/libreoffice-3-5
Most of the packages in this PPA have only experienced minor testing
-- in fact it is the place to enable a wider audience to test packages before they are published into the distro proper. In general, this PPA
is not for the average user to install without a closer look (if it
would be, its packages would be in the main repositories).
In general, users are advised to take a look at the changelog for the
details about a package. If there is a specific bug that is intended
to be addressed by an update released into the PPA, you are encouraged
to test, if the update solves that problem. Packages published after
the distro release are mostly such specific fixes. Critical fixes will
SRUed into the main repositories after testing anyway (later, with
more testing).
Installation instructions not included , but I assume are same as above.
Last but not least , the warning from Launchpad (this is general , for most (if not all) PPAs)
You can update your system with unsupported packages from this
untrusted PPA by adding ppa:libreoffice/ppa to your system's Software
Sources