I rather replay the interesting section (for complicated stuff even on normal speed) and speed-listen to what I know and what is easily understandable or booring.
With video tutorials I have the same problem. On normal speed I will work ahead, take a wrong turn because I didn't know where the lecture would go or drift off in to something slightly creative and than notice that I missed a section where finally something new was explained. So I have to skip back and find where I started missing something (Something really really annoying with audio material; No thumbnails, no search, no skimming backwards, mostly no identification possible from a single frame or word (the easiest way to find a part again, to which I listened before, is to remember where on my journey I was when I listened to that part and where that was in relation to where I heard what is currently playing)).
With video tutorials I have the same problem. On normal speed I will work ahead, take a wrong turn because I didn't know where the lecture would go or drift off in to something slightly creative and than notice that I missed a section where finally something new was explained. So I have to skip back and find where I started missing something (Something really really annoying with audio material; No thumbnails, no search, no skimming backwards, mostly no identification possible from a single frame or word (the easiest way to find a part again, to which I listened before, is to remember where on my journey I was when I listened to that part and where that was in relation to where I heard what is currently playing)).