I agree about the redesign, I tend to stick to old.reddit.com whenever I use reddit. And I think it might be possible to set a subreddit to stick to the old design. Yea, navingating a long discussion is always going to be problem, but I still think a subreddit might have some benefits.
There doesn't yet seem to be any broad rhyme or reason to our symptoms, and finding relief seems to be serendipitous. For someone new coming upon this problem it might be easier to decide what to try next if, for example, the "Usable Smartphones" discussion took place in a reddit thread where people could vote on devices/suggestions at the same time.