I don't often use detail in my descriptions of equipment sq, rather I use resolution. Resolution is perhaps the most important criteria of what creates sense of live performers in room. Resolution takes into account things like imaging, sound stage and detail. Resolution is holistic term under which detail falls under. Superior imaging, sound staging is in fact low level detail being resolved. And yes, added detail also heard as formerly burried performer within mix being more clearly heard.
Resolution and detail can also be perceived as a negative if tonality, timbre not attended to in high resolution equipment.
Resolution and/or detail is a qualitative estimate of equipment's worth, reviewers always going to mention this in evaluations.