RE: ESM Dornier DO 335
Engines do require a certain amount of experience and skill set to be successful, but they are far from difficult to operate reliably. Especially gas. Electrics have more of a plug and play aspect to them and I have found through the years that electric only fliers have a small amount of fear of engines.
As far as the sound goes, that is certainly debatable and I find the absence of it with the electrics quite annoying. Especially when the charge runs out. Dead stick with no absence of sound to alert you.
One day I will have a DO 335, more a matter of funds than desire. It will have engines.