What difference will upgrading PHP make?

I’m currently running Piwik off a cPanel VPS a PHP 5.2.17. I’m just wondering how much of a difference upgrading to a newer version (whichever works best with Piwik) of PHP?

I understand I’d have to purchase another VPS since I can’t run two versions of PHP side-by-side, thats something I’m willing to do. I’ll just have no idea how to setup/install a newer version of PHP. Is there any tutorials out there?

I’m also currently running Apache on CentOS, since its cPanel, should I use a different OS/Webserver or stick with these two?

Any help will be greatly appreciated!

try looking on a search engine for info on how to install PHP. 5.3 contains some memory improvements and bug fixes.