I feeling that I am contributing differently, assessing comments more on merit and adding my own thoughts less. I'm certainly voting on comments less (both up and down).
But I find I lack context in many of those discussions - when there are two different views on technical matters, I can't tell the difference in the group's opinion (especially if one is a reply to the other, so not comparable by which is 'higher' in the tree). Group think is bad, by blhack's mysql example is positive group interaction.
I also notice a similar lack of feedback on what is and isn't acceptable by the group. If a snide one-liner sits at the same level as a well-reasoned response, there's nothing to tell us all that one has 15pts in support and one has 1pt (an extreme example - other, more subtle ones, are now only noticeable if someone is greyed out for a negative score). There's no opportunity for us to learn from other's experience.
All in all, I want them back.