I had been looking forward to this one since we got the deck. While the martini is considered the Classic Cocktail and the sazarac is the Original Cocktail, the manhattan is considered the quintessential Old School Cocktail. The Drinker's Drink. The Dean Martin Elixir of Life, as it were. (Can you tell I'm partial to this particular drink?)
The deck calls for "blended" whiskey because, technically, the original recipe calls for rye whiskey or Canadian whiskey. Later, when bourbon came to replace rye as America's Premier Hard Liquor, that became the primary component of Manhattans.
Verdict? You really can't go wrong with this drink... if you like whiskey. I personally would only use a half ounce of sweet vermouth. Three quarters of an ounce makes it a bit too sweet, for my taste. And, depending on the whiskey and the brand of vermouth, I may throw a dash of bitters in, as well.
A hit! (Could it have been anything else?)
Trivia: the manhattan was created for Jennie Jerome, an American woman living in London, to help remind her of home. Jennie Jerome would later become the mother of Winston Churchill.