I prefer quality interfaces to quality implementations, as an implementation of a given component is usually easy to replace if requirements change, but changing an interface usually requires changing other components. So I agree with you that overall system design is more important that the particulars of any particular implementation.

However, I would want to know if you have the general idea that the way to solve some problems is to have a sorted collection or a ring buffer or whatever, even if you add on "but i'd have to look up the implementation details."