rhys_pesantsrevolt wrote:stun gun more efficient
More efficient than what?
Efficiency really doesn't enter into the problem. Anything that will give an electric spark will ignite a combustion spudgun. A 10KV spark is just as efficient as a 100KV or a 100,000 KV spark. Higher voltage will not increase the performance of the gun unless you do something like add a large number of spark gaps. (Even then, the increase in performance is probably pretty minor.)
The cost of a piezo is about the same as a stungun, especially if you have to pay shipping on the stungun.
Both piezos and stunguns have a tendency to crap out, especially if you only paid $10 for it.
Piezos are legal everywhere, stunguns are not.
Stunguns are a little easier to use in a remote ignition situation.
A piezo won't knock you on your ass if you touch the wrong thing.
A stungun needs a 9V battery, piezos don't use batteries.