As much as I like my furnace, if I had gas available I probably would have gone that way as it isn't expensive here compared to propane, oil or electric heating. I have lots of wood available thanks to Dutch Elm disease and now Emerald Ash borer. But sometimes, just sometimes it would be nice to just turn up the thermostat and not have the extra work.
If I were you, I'd at least get a comparative estimate on the gas boiler vs the Garn, just for the hell of it.