Care to share your experience with a tankless hot water heater? [View all]

[laundry_queen]

I'm moving into a new place tomorrow that has this. It also has a nifty new kind of furnace that uses the heat from the hot water that circulates to heat the house (and the forced air fan uses 50% less energy than conventional gas furnaces). I've heard some bad stories, however, about this type of heater not being able to meet hot water demand and needing a lot of expensive maintenance in areas with harder water, so I thought I'd ask here if anyone had any experience with the tankless system?

I'm pretty excited about living in this new energy efficient house, but don't be afraid to burst my bubble. I want honesty