This is a common discussion, Some folks swear by/at one or another type of heater but this is fact:
ALL 1500 watt heaters put out the exact same mount of heat, does not matter if it's a 20 dollar Big lots Special or an 800 dollar quarts tube job, they all put out the same amount of heat,, Some may blow harder (or not blow at all) some may make you feel warmer on the side facing them (While the other side freezes) but all put out exactly the same amount of heat.
So for a small "House" (RV) a small heater is my choice, ceramic cube.