I've been a member on other SE sites for a while now, but only recently joined SU. I found a few things a bit different here, and there are a couple of things I think could use some discussion.
1. Answering old questions.
Over about a 3 day period, I searched through SU questions in my speciality topic area (proxy servers). I spent quite a lot of time and answered about 30 questions, many of which had no other answer. Compared to other sites, I found the response to the answers (mostly no response at all) to be quite discouraging, and in fact learned that if you want to gain rep on here, you need to jump on new questions quickly, and ignore old ones.
This isn't going to get all those old questions answered. Many of the "unanswered" questions I saw actually had a perfectly good answer. Sometimes the asker just wanted reality to be different so resisted accepting the correct answer, or worse argued with it.
I know that "late answers" are reviewed, and so I think it would be interesting if reviewers were encouraged to give some kind of reaction to the answer, such as an upvote or downvote if they feel the answer deserves it.
In many cases these questions come up on google searches, and so an answer even years later can still be useful to people.
2. Lack of reward from the community compared to other SE sites
Compared to the other SE sites, it seems that people are much less likely to upvote an answer they see and find useful. I've had comments from OP like a variant of "thanks for that!", yet no upvote. I don't want to ask these people to upvote directly. I see it in a lot of other posts also, so often I will go and upvote something that I think deserves it, just out of a sense of redressing the injustice that the responder's effort was not appropriately rewarded.
Do people need to be reminded to reward other people's efforts when they are helped? Do they need to be reminded that they can upvote more than 1 answer if the answer is helpful?