Choose to install a release if you want to minimize risk.
Errors are corrected in development first. User-visible changes will be announced on the erc-discuss@gnu.org mailing list. see Getting Help and Reporting Bugs.
Debian users can get ERC via apt-get. The erc package is available in the official Debian repository.
Alternatively, you can download the latest release from http://ftp.gnu.org/gnu/erc, or your local GNU mirror.