I'll be honest, I have not seen a single implemented legal system I would like to live under, although that's not to dismiss all systems as equally bad. I was imprisoned in the USA once because an officer claimed a dog alerted, resulted in being stripped naked and cavity searched -- but that doesn't mean the entirety of our justice system is bad. Which isn't implied to be as bad as, say, a rapist getting away with it via a forced marriage as might happen under Shariah or xeer law.
The fact that someone can be temporarily jailed without any evidence or a change to challenge the charges is a painful compromise that the Founding Fathers made to balance justice (they themselves were at risk of arbitrary imprisonment by the Crown) with order (sometimes you see someone running with a bloody knife and you should arrest him before you trace his steps to find a corpse). Police departments try really hard to push what they can get away with, and there are certainly areas where I wish the courts would constrain them.