I think the difficulty of the problems should be increased a little. The set of 10 problems should be such that they cover a range of different algorithms and data-structures. I see that the first few problems ( 4-5 problems) of Codechef Long are solely implementation/math/greedy.
Also, problems should not be very heavy on implementation, as sometimes is the case. Rather, problem should test the analytical skills and knowledge of algorithms of the contestant, but should not be hard to implement after coming up with a solution.
Another point i would like to make is that subtasks should be removed from the easier problems (easy to easy-medium level problems), since the contestant gains nothing on solving these subtasks. Rather, some users get distracted from the full 100pt solution, and just code to get the “easy” points from the smaller subtask and give up on the question, while they could have easily solved the full problem, had they given some more thought to it. This is the sole purpose of Long challenge, improving by pushing yourself beyond your current limits.
Overall, I found March Long Challenge to be good one when compared to previous few long challenges 