Thoughts:
Surely it depends on how strong you are and what you're training for. 9a beasts wanting PE for their latest 70degree project would be able to (and want to) train on something much steeper than someone looking to train for the catwalk and who's aiming for their first 7b and thus could only probably use full on jugs on a 60 board which would - anyway - be totally unrealistic for their project...
The angle at the works seems good to me, though as a circuit fan I'd go for 2 boards and 2 angles if I had the choice.
I like circuits that go up and down not just sideways, the way the bristol walls do it is nice - circuits are marked by numbered tape/tags and you follow with the appropriate hand - 1=L, 2=R, 3=L etc. Allows much more vertical motion on less area, and holds can be reused on the same circuit.