It's nice that you don't have to use a func_get_args() call, shortens the code a bit. Being able to tell people reading your function that it accepts endless arguments is definitely a plus.
But what I'm really excited about is the possible to pass along endless references arguments (https://wiki.php.net/rfc/variadics#by-reference_capture). I've been searching for this feature, more than a couple of times, now I don't have to search anymore (now I just have to wait for PHP on our servers to be updated).