I use them in Chrome all the time, I have thousands — I basically search them as kind of a personal google... for those "Oh I remember reading an article about that once, let me find it"
Yeah, but how do you find that only from the title? Many times the title doesn't really represent what I remember about the article and that was in the corpus of the article.
Yeah it's a bit hit or miss because of that — I really wish I could literally make my bookmarks a private Google of content I've seen. Usually there are a series of things I try like "I think it was on X site" or a few keywords that I think were in the title. It works for me maybe 80% of the time.