They were useful during development but probably of little value for the user. The actual values are dependent on the tone stack controls so they are now calculated on-the-fly rather than being static values. I personally like the Grid Clipping set low because it has the NOS tube vibe. High values remind me of JJ's and Chinese tubes which I'm not a particularly big fan.I don't remember how useful the removed CF controls were but at least the new grid hardness control is fantastic. There seem to be no wrong values for it. Low values remind me of worn out older tubes and high values sound like fresh tubes, but no matter where I set it, it never makes the sound weak or artificial.