There is no such thing as "high" or "low" quality! You either have "quality" or "no quality". Simply defined: "Quality is conformance to requirements". Something cannot conform to requirements (specification) less or more. So, either you conform to specification or you don't conform to specification. The question is now: What are the specifications (requirements) for a cache? For example, the contents must be dry. If you arrive at a cache and the contents are dry - you have quality. If it is moist or wet - you have no quality. You cannot have half quality.