I would love to see opacity sliders for the individual filters in Color Efex Pro such that one could vary the overall strength of the various settings in a filter via one overriding slider. Going a step further, it would also be helpful to have an overarching opacity slider that would affect all active filters in a stack. This latter suggestion would be a useful alternative to adjusting the opacity of a Color Efex Pro layer in Photoshop.
Individual opacity sliders are already there… click the little triangle/arrow to the left of ‘Control Points’ on each filter and the opacity slider appears underneath.
Well, I’ll be! Thanks for pointing this out, Flashman.