I recently had a client request I replace the stock GH3 action in her Yamaha CVP-305 with a Yamaha Natural Wood action, and I had an opportunity to do some experimenting.
The Yamaha GH3 keyboard action can be replaced with the NW-GH3 action, the GH3X action, or the NWX action. All four of the actions below seem to be interchangeable, with the features as listed:
Her favorite action was the NW-GH3. Although there’s some subjectivity, we mutually agreed that the natural wood actions were lighter than the plastic equivalents (which is a bit counter-intuitive initially), and that the escapement added perceived weight.
In other words, we found that the NW-GH3 action was the lightest action, perceptibly, and the GH3X was the heaviest.