Excellent review. I agree with you and M.J. on the superior all-round character of this fine spirit. After a copious christmas dinner, for me nothing has beaten the Highland Park yet. It is in fact so good that other famous scotch whiskeys can be a bit dissapointing after the HP. One of the best I've had so far.
I've had the 18 and the 25. The 18 just shot up in price around here from around $60 to $80. It's very good, but I don't know if I can would pay $80 when I can still get the 12 for $40, but if you can find the 18 for around $60 pick it up.
Now the 25, is the best Scotch I have ever had in my life, it's absolutely magnificent. Now for the downside, it's $300 a bottle.