debug kits are interesting but not as intersting as dev kits in my opinion. the nice thing about debug and dev units is that you can use hacked software to load retail code...almost eliminating the need for a retail xbox (although i wouln't use it as a replacement). debug kits will also run burned disks and homebrew quite easily with only a few software modifications. the retail console can do this as well but the process is a bit more invasive.
Well f*ck me, what exactly did you want? ...A Debug Kit means f*ck all to 99.99999999999% of the population, but to anyone that uses one seriously it's a bloody gift from the God's!!!! ...There's a reason for everything, if you don't have a reason you won't need an answer.