No experience camping with electric heaters, but just keep this in mind. All of them are exactly the same efficiency. The only way you'll get any more efficiency is with a heat pump. So spending more money on a fancier heater won't get you any more heat than the cheapest little blower style or whatever.
This. Put in technical terms, what makes you warm is BTU's/hr. Say you need 20,000 BTU's/hr to heat some arbitrary camper space. Propane contains ~21,500 BTU per pound. Assuming no efficiency loss (and there always is), a 20lb cylinder will heat that space for 21.5hrs (21500*20 / 20000, the math just happens to work out neatly here that's all).
Now consider electric. 1 watt is 3.41 BTU, so you would need to produce ~5900 watts to run an electric heater to produce the same heat. And it's actually far worse because a gas generator -> its AC output -> the heater will have more losses - most generators are only around 20% efficient, so multiply that by 5 and suddenly you need a 25kW generator just to get by. It doesn't matter whether you have a direct radiant electric heater or an oil-filled one. The oil filled ones just store some heat so after they're shut off they keep warming a room. The heat that went into the oil still came from the same source - it doesn't put out MORE heat, it just stores some for later.
Electric is just about the worst way to heat any space unless it's literally your only option or you have a special case (like in-floor radiant, which still isn't that great). It's not that the heaters are actually all that bad - they're pretty close to 100% efficient, actually, because literally all they're doing is converting angry pixies to heat. What they lose goes to making the filament red which is why they glow. They're just crappy light bulbs.
If you want something efficient and simple, stick with a Mr Buddy or anything in propane land. If
moisture is your main concern, look into diesel heaters. They're incredibly efficient, sip fuel, and put out very dry air because of how they're designed. They're cheap, too. They do take power but just to run their fans and glow plugs while starting, so even a modest sized 12V car battery can run one for a week or more. No generator required.
Anyone else camped near you will thank you.