Got the Skinomi Edge to Edge for the S4 in today, and just finished installing it on my watch. Size is perfectly cut to the entire front glass, including the bezel parts. My first install attempt was a fail, I couldn't get the edges to stick after trying to hold them down for several minutes. Second attempt I heated the edges of the screen protector with a hair dryer after applying it to the watch, and then held the watch face down in the palm of my hand for a few minutes. That did the trick
It's currently drying, but I can probably post pictures in a few days if anyone is interested. Just waiting for the micro-bubbles and clouding that typically happens after a liquid/film install to disappear.
I'd say if you like Skinomi (or other film screen protectors) in the past then their S4 offering is a solid choice.