At first I though someone was running a semi or an older Dodge diesel through the campground!!! Yes ours is loud, but I have gotten used to it and my husband uses earplugs. We have spent about 60 nights in our 303 and have used the furnace enough to use a tank of propane.
Hiya helicopter and welcome to the forums!
Congrats on the 303
I have the Solitude and have only ran the furnace once. In the Solitude, it didn't seem to be too loud.