It happens to me once in a while that I want to open some contest on CF to have a look at its problems, or attempt a virtual contest. Of course, for that I need to pick a contest, but (unfortunately?) the quality of problems here is inconsistent and I just need to hope I can pick contests with good quality.
For this and other training purposes, I think a feature to rate contests (possibly using the same system of upvoting blog posts or comments) can be very helpful. I don't think a contest should have the same upvotes as its announcement, since it's common the announcements get downvoted for technical issues like a huge queue, or server crashes, which don't affect virtual participation.
What do you think?