Well, here's my two cents worth...
#1, I wouldn't base my decision on a stove... only if all else were 100% equal.
#2, all stoves and or ranges/ovens require a fuel... but all fuels on a boat are an issue and have to me properly contained or set up/ventilated.
Given #2, and the fact that I too have an alcohol stove that I do not trust (its 30 years old)... we did a sort of propane conversion using a camping stove with the small disposable propane cylinders. Last year we just set it on the old range when inside, but this winter I plan on incorporating it into the original alcohol stove frame (although still removable).
Personally I wonder about the use of LNG (Liquified Natural Gas) as its lighter than air. But I've not seen anything on it... Have any of you?.