I would like to suggest Rating system for Contest.So If a Conest has Good rating people would like to upsolve problems
Care to elaborate more? What exactly you want?
I think rather there should be difficulty rating for problems like in codeforces, so people can choose problems for practice. I just find codechef difficulty assignment way off, maybe the reason is that many were meant to be for long challenge and they might be easy if time to solve them is 2-3 days but still many problem which are not easy should not be there in easy section.