You won't get the best possible picture settings by using someone else's settings, just like you won't get the best possible clothing fit by taking garments off a dummy.
ISF Dark setting might be a better start point for making further adjustments because most of the picture enhancement crap is switched off in that mode. This is a bit like starting out by choosing the correct-sized off-the-peg garments as a start point for having some alterations done the get your final fit. You still need a tape measure and someone who knows what they're doing to make the alterations, but you stand a hell of a better chance of success than beginning with clothes that are a million miles away from your size.
Fine-tuning your off-the-peg settings is best done with a set of test patterns. Some Blu-ray discs have basic patterns in the extras. The AVS site has some download able ones that can be played from a network or USB device. There are also Blu-ray test discs with a comprehensive range of patterns and test for the enthusiast to get the best from their own system. At the pinacle of set-up is the bespoke tailoring option of a professional calibration.
