I have a truma e2400. Which is very very similar to heat a big van (7.25m iveco conversion)
I like it , it’s thermostatic so you can set to maintain temperature with a low fan speedand it will cut in and out to maintain it and I can’t hear it from my bed 🙂 – thermostats in the remote switch not the unit
As for gas consumption – I haven’t had to change the gas yet and I’m running a 6kg propane. It needs changed now after about 30 nights away in it this year – many of them in February and march so heating was used lots.
Only downside I see is the need for gas. The diesel heaters at least you know you’ll always have fuel.
-although I need it for fridge , stove and BBQ….. So looking at gaslow or gasit underslung tanks