This is John Apodaca from Daddy-O's Martinis and I believe that glass size for cocktails really does matter. As a bartender and cocktail enthusiast I research recipes from vintage cocktail and bartending books from the 19th to the first half of the 20th century. Most of the ingredients in these recipes will equal approximately three to four ounces per drink. Originally, cocktails were served in 3-4 ounce glasses. A recipe that size means the cocktail will remain cold and flavorful to the last drop. As a fellow bartender (Jason from 320 Main in Seal Beach) says, "the last sip should taste as good as the first one". I agree.
Todays cocktail glasses are usually seven, nine, twelve and sometimes thirteen inches in size. Most people would think, "I'm getting my moneys worth," but in essence, once they are finished with half the cocktail the drink loses it's initial chill, the flavor is lost, and person will have to order another or finish the drink quickly rather than sip it. Serving drinks in smaller glasses allows one to savor the flavor, as well as enjoy more than one drink without becoming too intoxicated.
If you prefer a cocktail served in the classic style, have it served in a 3-4 ounce glass. Both James Beach and Canal Club in Venice Beach, CA, as well as Musso & Frank Grill in downtown Hollywood serve cocktails in glasses of this size. You can find this stemware in restaurant supply stores such as Surfas in Culver City, CA, Bar Keeper in Silver Lake, CA, or even sometimes at Ikea. For further reference, check out the book Craft of the Cocktail by Dale DeGroff.