In reply to Simon Caldwell:
They are top-roping a few 1 star routes in a quarry in the peak district, with an excellent crag literally over the road as well as half a dozen crags within a few minutes drive. No one will have travelled far for these particular routes at Lawrencefield (rather than, say, climbing in the Peak District).
By top-roping they will only occupy 3-4 lines at a time for a few hours whilst enabling 30 climbers to all get a good number of climbs in each. If you split this up into leading pairs they would take over a much larger percentage of the crag as well as taking a lot longer per climb. With the new climbers concentrated in one area, experienced members can coach on proper footwork and climbing technique in a way that's more difficult when belaying from above.
They have said they will do their best to be tidy and not be a nuisance, and I'm pretty sure they will move their ropes for you if you want to turn up at 2pm and demand to lead Gingerbread Slab.