here is a link to how my APC is running : [removed]
As you can see, it fills up pretty quickly and my Cache Full Count goes over 1000 sometimes
My website uses W
You really should set apc.stat=0 on your production server and it will prevent APC from actually going to the IO to check if the file has been changed.
Check out documentation first: http://php.net/manual/en/apc.configuration.php