There will soon, or there is supposed to be, a free version of ACF5 on WP. This free version of the plugin will include this function. So at that point, the existence of this function won’t really tell you if it’s the free or pro version that’s installed.
Exactly what functionality do you need to change depending on if it’s the free or pro version? If you give me more info on that maybe I can suggest a better way to do the detection.
