Insitutions have been given their own version of the contrast between the clarity (but inflexibility) of a prescriptive regime compared to the flexibility (but lack of clarity) of a priniciples-based approach in Rob Everett's speech to the FSC conference on Wednesday. Philip Macalister has good coverage of this, including the quote from Everett, CEO of the FMA, at this link. .
I invite you to make a further contrast with the case of Southern Response Earthquake Services Limited versus Dodds. You can read the details at this link. Papa draws attention to the desire to work with clear rules, rather than a broad duty, with this time, the government being on the rules-based side of the argument.
My personal preference is for a principles-based regime, provided it stays that way, and regulators and insurers stick to principles - and don't gradually develop a shadow rule book which means we end up with the worst of both worlds.