Who reads all the posts in a hot topic?

I’ve noticed that there are many topics that arouse heated debates resulting in long discussion full of posts. As much as I’d like to sit and read all the replies, I don’t have the time to. And then, if I have a comment I’d like to post, I loathe to as I feel that someone has most certainly already posted the same idea.

How many of you all actually take the time to read all the posts? Or do you just post your comments regardless of whether someone has already made the same point?