I'm also using Ubuntu. After 5.10.1 was released I decided to upgrade system perl. Of course I was aware that replacing system perl is not recommended practice, and it may cause numerous problem, but it didn't stop me. I've get source packages for 5.10.1 from packages.debian.org, built and installed. I'm using it on all my desktops since September, installing modules with cpanp (they go in /usr/local), and quite happy. I didn't get a single problem. There are no conflicts, as cpanp installs modules into /usr/local and packaged modules are installed into /usr.
I don't want to say that you should ignore recommendations of previous posters, but just informing you that I did and got a positive result.