This new version, is tagged as beta, mainly because it introduce a new feature, the serializer can be selected in the configuration file. So, it's now possible to use the one provided by the php-igbinary extension.

As always

yum --enablerepo=remi update php-pecl-apc

Don't forget to install the control pannel (file /usr/share/doc/php-pecl-apc-3.1.7/apc.php) which allow check the cache performance and to tune the configuration (/etc/php.d/apc.ini).

This extension, maintained by main PHP developers, will be include in next PHP major version (5.4), disabled by default. Which probably explain the rise of activity on this extension.