The distance gained by Link using the 'step-dash' is minimal compared to the distance covered in the same amount of time simply walking. To give you an idea, you can only reach about one square further than a walk on miiverse in the same amount of frames using a step-dash Jab/Grab/U-tilt and maybe 1 and a half for F-tilt, and that's if you get it just right. (I was able to re-create it using frame skip inputs in training mode so I could get it perfectly with precision every time for testing purposes.)
What the video does not tell you is how incredibly finicky this all is. A difference of a single frame anywhere in your input can mean the difference between getting the kind of slides showcased in the video, or accidentally dashing, getting no slide at all, or getting a notably weaker slide. This tech is not easy, so for the chance of getting a slight increase in reach with the high risk of getting less reach or some other action entirely, I say it's not worth our time.
As for approaching with the Hylian shield, I assume you mean by activating the step-dash with a crouch, but what you fail to realise is that the Hylian shield will not block projectiles while in the transitional state of going from the standing position to the fully crouched position (or back up). So by the time you are fully crouched and your Hylian shield is activated once more, the distance covered will be almost at an end. If you want to approach with the Hylian shield, just walk. It will get you there pretty much just as fast, and it will actually block projectiles for you the whole way.
Finally, for those wondering, no, you will not get some super effective slide if you use this after a bombslide.
Just saying. 
