Plus for the infrared heater. As for me, it is more convenient.
+ Saving electricity with an infrared heater is very significant. If an ordinary heater consumes thousands of watts, then, in this case, the bill will go to hundreds.
+ The speed of heating the RV is very high, infrared radiation does not heat the air, but walls, furniture, etc., which then return heat to space. Also to the pluses of this type of heating is the fire safety, the fact that they do not burn oxygen in the room and do not dry the air.
+ There are still film heaters, they are usually used to heat the floor. (BTW they are really good)
So as I said before - the infrared heater is a good choice considering that there a lot of options where to place it, how large it would be.
Here are some pretty cheap models suitable for RV -
https://www.bestadvisers.co.uk/infrared-heaters. However, I would advise you to choose smth from Pion, it's not the most famous manufacturer, but nevertheless, I use it, It showed him the best in 2 years of using.