I actually had a sample bottle of the Mac 18 a while back and really liked it, to me was a definite taste above the Mac 12.
Shame on me for the 3 unopened bottles of Balvenie Portwood 21 but I don't remember ever hearing of anybody not liking the Portwood, and most comments that I have seen in print lean towards worshipping it over most other expressions. So, oops, my bad, I'm either 3 times an idiot or I am in heaven. I'm betting on heaven. I will look for the Toshan 21 YO. And, furthermost, I especially appreciate and respect your opinions.