I actually save time by visiting CF. Reason is I don't have to visit other sports, news, politics or pop culture sites anymore. This place is a one stop shop. If something happens in the world, there will always be a thread about it, even sometimes three threads on the same subject. When I wake up, I don't check CNN for the news, I visit this place to get the news.
The only days I have not spent at least some time on CFs is when I don't have access to the internet. That is a very low number of days over the past 6 years, given that I always face a computer at work. As for how much time, I can't really say. Because I mix it with work, it's hard to estimate. But I'm guessing it's A LOT.
