This may sound like heresy to most of you, but bringing down the whisky down to 30% ABV (or 60 proof) might allow a fuller appreciation of the aromas and flavors.
It will probably also allow you to differentiate the different whiskys a little easier. Don't take my word for it, just read what Charles MacLean, an editor at Whisky magazine has to say about it.
http://www.whiskymag.com/nosing_course/part1.php
My favorite quote of Charles' is when he is asked what his favorite whisky is, he replies...
"The one that's in my hand".