People have different learning styles I think, I don't think any one style will win over another.  Some people will prefer to read, others watch and or listen.  I think written tutorials will always be about, probably more so than videos.

My dyslexia makes reading and understanding tutorials difficult, I do much better with a video.  Consquently when explaining something, I do better recording a video than I do writing it down.

Sound recording quality is also down to the soundcard in your machine.  I found this out early on when I got too much hiss in the background, I researched a bit and bought an external USB Soundblaster Platinum and kerpow :) it cleared up my recordings a treat :)

John.

Fugazi (without the aid of a safety net)

https://www.facebook.com/Fugazi3D