I feel it to be an affront to "good" Bourbon to use it in a Manhattan, a drink in which the Vermouth (and almost obligatory drop or two of Angostura bitters) substantially alter the flavor of the whisk(e)y. Likewise, Manhattans may be a waste of the few remaining "really rye" ryes.
Always remember that "cocktails" like Manhattans were developed and became popular to mask the raw flavors of available distilled spirits.
In my perspective, there are two families of the genus Manhattan....
Upper Manhattan - a decent Canadian blend like CC, 4-5 to 1 with Noilly Pratt Dry (White) Vermouth, no cheery but a twist of orange peel and the option of a little bitters. Lemon peel substitutes for orange among those who want a stronger aroma.
Lower Manhattan - Bourbon, a decent bar brand, but never "Sour Mash", "Sweet" Vermouth, Cin-Cin being traditional, 3-4 to 1, almost always bitters, a stemmed cherry, and the twist of orange peel which rubbed on the rim of a chilled stemmed glass and then twisted into the drink, adds an aura and broadens the flavor parameters.
The use of fine whisk(e)y in cocktails represents a gross violation of good sense, good order, and high moral values, a descent into a level of depraved indifference and degeneracy unacceptable except among primping, pompous pretentious pontificators, nattering nabobs as a former Balmerian used to call them!