Seems like a low-cost way to try out a novelty item or, as several have commented already, a fun stocking stuffer.
Personally, though, I'll stick with ice. Most rye and bourbon - and even some Scots whisky - benefits from some water to "open it up." A couple of ice cubes made with good quality (well-filtered) water and protected from "fridge flavors" is a plus.
I like how the liquor's characteristics reveal themselves differently as the cubes melt in the glass.
So - probably a pretty good deal and good opportunity for a trial run. But we're still gonna pass.