Whenever I see something I like, I vote it. It feels awkward to me to type a bland show of praise when many other users have already done (and will continue to do) the same*. When I see something I dislike or disagree with, I feel it easier to go into more detail as to why, as I rarely see people sharing similar criticisms.

* As a sidenote, people who just say "This." and "Cool." irk me, and I don't want to elicit the same annoyed reaction in others.