amen!
I put a webasto hot water system on my 410 and absolutely love it. Even in the summer, it's great to be able to enjoy a hot shower out on the hook without having to start up the engine. And when beating to weather during an all-night passage, it's great to have warm air coming up the companionway. I installed Webasto's smallest system and find it to be completely adequate. It's light and tiny and it takes surprisingly little fuel. Tends to be noisy, though. I put mine in the transom, especially during startup, and we can hear the pumps whine through the bulkhead in the aft cabin. A small price to pay, if you ask me. If there's one downside, in comparison to other systems, it's that the radiators tend not to dry out the cabin the way a forced air system does, because it heats air already in the cabin. It's much more efficient, though, both on fuel and amps. A fringe benefit, by the way, is that you can route the hot water lines under the sole in such a way that the floor is toasty when you bare-foot it out of the berth on a wintry morning.