Yes, if it's adjusted right, there should be pretty close to complete combustion of the diesel and no smell.
We have the new ITR Oasis unit, new guys in the market. You can not smell diesel when it runs. Many think it's an onboard generator because I added a nice chrome exhaust. It can be loud though, about the same volume you get from the outside exhaust of a propane RV heater. My kids were not happy the last time they had a campsite on our passenger side and the campground only had 20 amps. Had to run the burner and they could hear it fire up.