I follow about 7,000 users, most of whom I don't know personally but have followed because we're in the same industry. But I don't ever attempt to read my feed beyond a couple of minutes. If a Tweet from a user I care about gets drowned out by 20 tweets from the randoms I follow...it's no big deal. I follow enough like minded people that many of them will retweet something that I want to see. And I like seeing random stuff from semi-random people...that to me is what Twitter is for.