discerning

having or revealing keen insight and good judgment; "a discerning critic"; "a discerning reader"

unobtrusively perceptive and sympathetic; "a discerning editor"; "a discreet silence"

quick to understand; "a kind and apprehensive friend"- Nathaniel Hawthorne

able to make or detect effects of great subtlety; sensitive; "discerning taste"; "a discerning eye for color"