Jay, I do appreciate your post of the material, as my thread was hopefully going to be useful to more than just me. However, I did mean to make fun of my tendency to get analysis paralysis with print-outs out the wazoo!!! :-) Beyond that, the reponses have been very helpful.
As I suspected the propane heaters do run cleaner. However, I do worry about the downsides of the propane system: fuel leaks, storage and filling of tanks, etc. I do like the propane heaters I have looked at in that they pull in outside air and come in sizes that would fit my cabins nicely. But, I keep coming back to the frequent need to refill them: the usage rate is about 7 hours per pound on low.
While I am not surprised by the soot issue with diesel heaters, this is an issue I have heard less frequently than I thought. Like anything, good maintenance regimens are important, but diesel doesn't burn clean and our hulls often show the marks of our using the engine. I have heard of the large heat output. I do like the ability of minimizing the amount of fuels kept on the boat not just for safety, but simplicity. With whatever system we choose, we are installing a CO monitoring system in order to keep safe.
I spoke with a friend who lifes on board in Boston and he just installed a diesel heater in his Tayana 37: a SIG 100. He likes the fuel simplicity, but hasn't run it enough to comment on the presence of soot issues. He did say that a neighbor of his has an Espar system and takes his "glow-plug" out each week to clean it. This may well be over doing it a bit, but the level of routine maintenance is a consideration.
As with most things, trade-offs and compromises are present. Our initial usage will be very seasonal and light, but the potential of sailing down south during late Fall is high with living aboard at some point a possibility. Using the ICW as a proxy, heat would probably be needed most of the time until well south. Initially, the propane option would probably be best, but if the journey down south late in the season or living aboard was the norm, then an easier to fuel system would be better.
Well, I really appreciate the opinions of others on this. The Espar system I looked at was relatively clean, good BTU's, and economical with fuel, but WOW it is expensive and somewhat fussy. Propane and Dickenson/Sig style diesel heaters are relatively simple and have big DIY potential. Anyway, more to think about before I decide.
Doug