Certainly propane is less safe than alchohol and makes a big bang when safety and maintenance is not attended to properly. Still...most of the rare explosions one hears about are the result of carelessness or neglect rather than "accidents". So...I am comfortable using propane as a fuel and vastly prefer it to alcohol as a convenient and effective cooking fuel. I have owned alchohol stoves before and remember waiting forever to try to get a large pot of water to boil. While there may be improvements in more modern alcohol stoves...the heat of the burners can't be that close to my LPG stove. I have never seen any tests of this and would be happy for a reference...but in the meantime will submit a link on camping stoves. One would think these would be designed for maximum efficiency since you have to carry your own fuel. The table shows all of the alchohol burners taking 2-3 times as long as the gas stove to boil 2 cups of water.
That is similar to my experience on board.