Samsung changed the left soft key from a menu key to a recent apps key. This does not mean that the menu functionality has disappeared. It's simply hidden. All you need to do is long press the left soft key in any app. See the video below;
You can activate voice control on the Galaxy S5 by simply saying smile, cheese, etc. This is particularly good for selfies. Samsung has hidden this option in the camera settings but you have to scroll to find it. Sounds obvious but believe me, it's not. See the link for a video.