I tried "7 & 7" when Travolta made it popluar in the disco era. Then I discoverd Seagrams VO and that Canadain whisky is Sooo smoooth. Blended whisky is good.
I switched to "VO & 7" after that. Call drinks are more expensive than well drinks, so sometimes I will make it a "Canadian and 7". Once my drink got mixed up with a ladies drink at the table: she remarked 'this is good!! what is it ???!!"
BTW, I've had Canadian whisky in Canada (VO, of course) and a Singapore Sling in Singapore (@ the "Long Bar" in the Raffles Hotel, of course). I don't like Scotch but the "moral imperative" there is .....
Mustang