Somethings up Dune. Your solution is by bar more elegant (it seems in life I prefer the overly complicated, round-a-bout path), but mine does work I swear I swear

I've posted the file, if you (or anyone) is interested.
The blue node you're looking for luvsmuzik, I think: right-click in the node view, select Function -> Convert -> Displacement to Scalar.
...at least, I think that's the one you're asking about.