Would be nice, but boosting is a bad problem with those. My ranking idea above, you could farm and crap for your SP if you found a way, but boosting in a playlist will only get you raped by good players if you do boost, since the individual playlist rankings don't count for your overall rank. It's an OK idea that I spent a couple of hours working out. Could be something better, we just don't know it yet. My idea is just an idea and 343 probably have some nice thing in store for us.