Tough call. I didn't have any Macallan on hand when I was trying the two Japanese whiskeys to really dig down into it, but I think I might like the Yamazaki better. But then again, I am a boring Scotch drinker at this point. I don't care for/haven't developed a taste for the Scotches that have stronger smoke or peat flavors.
I have a bottle of Yamazaki 12yr. I remember not being very impressed with it. While it was non-smoky, it also lacked the hint of sweetness from a Sherry Casket-aged Macallan (my preferred Scotch): "Dry" and a bit bland. I usually pour a shot of Cask strength Macallan Sherry. If I really want something special, I open my bottle of 15 year Macallan (sherry)...
Talisker (more smokey) and Lagavulin 12 yr (whoa, price has doubled since I last bought. Glad I bought 2 bottles) are also very tasty and not too smokey.
Mrs. Forbin can't do Scotch, but loves John Powers!
For a blended whiskey that was super cheap the last time I bought a bottle or Powers, it was SMOOOOOOTH. An easy drink, but not much flavor.