Cycle Sportives

i bow to your experience on this one, but very confused by their home page description (duh... why refer to DB if it's not actually on the route?):

"In cycling terms, the South Downs are famous for the epic 100 mile South Downs Way off road ride along its length, while on the road, the best known feature is probably the Ditchling Beacon hill climb on the London to Brighton"

I'll probably be doing this. It doesn't go over Ditchling though as it's run over the western end of the downs. 2000m of height gain doesn't sound huge compared to some sportives, but I know the area quite well and it's all short steep climbs and not much flat for any distance.