Gray: I've been using my Taylors model 068 - a kerosene with alochol start heater - and it can really make noise also - though not much heat IMHO. I do have a blue flame in the combustion area and I do "clean" the jet.
The outside of the unit lower unit can hit ~150-200 deg and the stack can hit 200-300 deg. The Kerosene seems to burn pretty clean - but yesterday when it was 49 deg outside I got some of the cabin to be 60 deg - after a while running/roaring!
Update 02/17/13: The admiral really apreaciated the heat from Taylors model 068 this weekend. To easily start the heater, add 10 CC of alochol in the wick tray below the burner, light the alochol and let it burn almost out. With a barbaque propane lighter, light up the kersone burner but at a very low setting. Let the burner continue to heat up the burner elements and gradually turn up the burner. With the methond above, I was able to light the heater w/o the smell of unburned kerosene or alochol filling the boat. The key was to let the burner elements heat up.
The 12v fan is turned on low after the unit is up to operating temp and distributes the heat in the cabin but not the V-birth. I'd say that at 45 deg and above the heater would bring the cabin temperature up by at least 10 degrees - below 45 degs I would like a heater with higher BTU output.
Jay