The quality of a particular level is highly subjective to opinion, so it would be very difficult to come to mutual agreements unless one level really stood out from another in terms of quality. JCS "wars" can be fun and rather amusing, although I don't think a ladder would be the right way of promoting level creation. The main problem is that there's simply too few active JCSers at the moment to have a proper competition. Also, as FS just pointed out there's bound to be arguments. With a clan ladder it's clear who is "better" based on who wins the games, whereas there's room for debate on what the better levels are. I personally do not think a JCS ladder will work, but feel free to prove me wrong.