Metro,
A graders only at this stage, a couple of reasons for this;
1. time limits mean that not all A graders will even have the opportunity to lodge a time before the end of the month.
2. the speed and endurance required to crank out what ends up being 7 laps flat out after 3 laps getting up to speed, would result in our non A graders not being in touch with the derny at the end of the effort.
Lets see how this one goes, and we can massage it a bit for some more challenges next year. Its definitely something to look at having some training towards.