Just watched a video where a cheap (under $200 Chinese Copy) is compared to an Espar Diesel heater.
The Espar is about $1400 US compared to the Chinese copy about $130 US
I have 3 Chinese diesel heaters. I have had only one problem with one of them and that was a poorly made fuel tank, not the heater itself. I never have any odors of any kind whatsoever from any of them except maybe on initial startup and it’s rare and very slight if at all.
They have been 100% reliable and kept me comfortable on some cold winter nights. I found that my 5Kw unit is too much for my small van even on low. So I also have a 2Kw unit that seems about perfect even though I still keep a window open slightly on nights down to 10F because it puts out plenty of heat even on low. I do have custom made window insulation covers and that helps as well.
My (opinion) is that if you have trouble with your Chinese diesel heater you either got a bad one and should have returned it early on, or you just don’t quite know how to use it. I also have buddy heaters and they are good for their purpose but I much prefer the diesel heater in the van for a number of reasons.
If the Chinese had not made affordable copies, I would likely have never owned a diesel heater.
The only thing that could make them better for me is if they were made in America for not too much more.