Understanding heaters.
First a watt is a watt is a watt. What is different is how various heat sources warm you up--not how they heat the air.
Convection heat the air and then the air warms the objects. Often these include a fan to help circulate the air. The safest of these are the oil filled units, because the surface of the heater doesn't reach the combustion point.
A radiant unit heats the objects which then radiate themselves and warm the air. Typically these are ones that glow "cherry red". I love how these work--but they need to be used in a prudent manner.
My favorite heat source is the electric heated carpet. No more cold floors.
I find oil filled units lovely for use with a generator or when there is limited shore power amperage. Warm up the rv--then shut down. The warmed oil will "coast" for a time. At night I use the battery bank to operate a heating pad. When I feel cool, I'll remote start the generator, turn the oil filled back on--and of course recharge the battery bank.
I can, and do heat 100% electrically.