Bourbon, yes. The thing to remember with bourbon is, the more "mainstream" mid-tier bourbons all have water added to them. Think Makers, Buffalo Trace, Bulleit, etc - that's why they are 80 proof. You move up a little and you get into the Cask Aged category where you'll find proofs like 90, 100, 110...whatever. These tend to be un-cut leaving the most dominant barrel flavors present. A good example of this for ~$50 is the Woodford Double Oaked bourbon. They purposely didn't cut it down because that would take away some of the barrel flavors that came from double barreling it, thus leaving the consumer with the ability to cut it to their tastes.
In my opinion, a cask-strength bourbon should only be given a couple drops of water to open up the flavors a little bit. Once you drop an ice cube in there, you've unleashed a good amount of water. It's also going to drop the drink's temp which will impact flavor (think of how it's good to slightly chill a red wine, but you don't want the wine over-chilled).
Fun facts on ice: If using ice, the sphere cubes are best because they have less surface area and melt slower. A good whiskey bar will use a single large sphere or square cube, and you should be able to see straight through it - that means the ice cube was built up slowly over the course of 12-24 hours, and it will melt slowly. If the cube is cloudy that means it was hastily frozen and will thaw just as quick (think of your kitchen's ice maker - it's quickly made ice, and it's cloudy).
If that fails, I can list for sale on HBT and avoid ebay fees. 
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