I haven't been watching any of the playthroughs at all yet. I've seen enough to know that I want to play it, and then I have been avoiding anything at all besides written articles.
Once it is released, I might check out a few what if I did this sort of thing, but an actual stream, probably not. I got the game. I can play it if I want to see the game?
Side Note: Snape kills Dumbledore
Funny story...my brother spoiled that bit there for me
But I'm with you. The most I'll do is look up something if I'm confused or curious about something, but I probably won't go anywhere near a video for awhile. Articles and forums like this are pretty good about hiding spoilers.