Cheers for the words of reassurance guys
The improvements from my previous settings are noticeable, now giving me a much more natural picture but also with more punch, so to speak.
I've gone a step further since this and bought ControlCAL to activate and calibrate the ISF presets and I've achieved an even better picture, with similar accuracy as the above movie mode but with more headroom to push the peak white higher without clipping, giving me much greater impact.
I love working with CalMan and this calibration business is really quite addictive