I don't think Miles is registered on here so I will pass on all the great comments and feedback from this thread.
It is worth drawing attention to the Goliath zip lower in Ch3W which goes from floor C to E. Information about Goliath can be found on Miles' anotated map in the link Ant89 posted.
This zip is so steep that if you rode it like a conventional zip it would result in a fatal impact at the bottom. ;(
120m of rope is needed to lower participants safely and under control to the bottom. There will be warning signs about Goliath at the top of it, and the official Go Below stance will be to request visitors to Cwmorthin not to use it. All Go Below trip leaders will receive specific training in it's use.
There is still some work to do on the course, and I think Miles is in there even as I write bashing away at the finishing touches.
Thanks again,
Chris π
If it's raining, put a mountain on your head