Concierge.com's insider take:

Dapper in his dark suit, distinguished in his courtly manner, and wrinkled with cocktail wisdom, Fernando del Diego presides over his warmly lit zinc bar with a level of precision and humble attention to detail that is a revelation even in a city full of great bars. House creations include the Diego, with vodka, kirsch, lime, and melocotón (a sweet, red squash-like fruit); the soltero tranquilo, with vodka, Calvados, lime, and blue curaçao; and one of the best-balanced mint juleps in existence. Yet to focus merely on del Diego's recipes is to appreciate only part of his talent. Stop and take a moment simply to watch the master mixologist's hands—the measured flick of ice cracker against cube nestled in his palm, or the quick, compact full-arm shake that kicks up a froth neither one millimeter taller nor one millimeter shorter than is intended. This is where an Adrià foam meets a Federer forehand, and it's much appreciated by the thirtysomething local crowd, who are here for the cocktails rather than to be seen.