[Firefishy]

Pretoria was mostly mapped by a single mapper very early in the project. There wasn't high quality aerial imagery available when he literally cycled every street in Pretoria.

Because the map "looks complete" Pretoria hasn't really attracted many mappers since his departure.

Cape Town has a much more vibrant community of mappers. I've also been able to get crazy high resolution aerial imagery for CT from the municipality which helps: http://coct.aerial.openstreetmap.org.za/