And what Japanese single malt are you talking about? I've never seen a Japanese malt, and I love whiskey.
I don't think you're missing out on much.
Suntory's Hibiki 17 year old (a blend) is one of my top 3 whiskies

. I don't care whether it's a single malt or blend. If it's good, it's good. "Blends" aren't just a concoction of leftover single malts. Blending is a craft, and if done correctly, the product ends up better than a single malt due to the overall resulting character.
As for the other Suntory whiskies, I don't think I'd buy a bottle of Yamazaki or Hakushu 10 or 12 y.o. (single malts) unless I was buying (and drinking) it in Japan, where it's cheaper. It's not worth it, IMO. I like the Yamazaki, but I could live without Hakushu.
Nikka's Taketsuru 17 year old is also very good (their 12 y.o. is not), but it isn't as good as Suntory's Hibiki, IMO. The Yoichi 12 year that I tried is pretty awesome, but if I remember correctly, I've only had the 12 year. I've also seen a 15 year old bottle, but I don't think that's the one I tried. Perhaps it is?
My recommendations are the Suntory's Hibiki 17 year, Nikka Yoichi 12 y.o. or older, and Nikka Taketsuru. The rest isn't something I'd rush out to buy. Not enough peat, or complexity for the price.
For the price of a Japanese whisky in Australia, I may as well spend the money on a Laphroaig Quarter Cask.

For less than a Yamazaki 12 y.o., I can get an Ardbeg 10 y.o., or something with a bit more caramel/honey.