Downside to high-efficiency furnace?

Reliability rumor examined

Q: Is a high-efficiency furnace more likely to break down compared to a mid- or low-efficiency one?

A: High-efficiency furnaces, those with a rating of 82 percent to more than 96 percent efficiency, are designed to extract and utilize some of the waste heat that would otherwise be exhausted out through the flue. Accomplishing this task requires additional fans, valves and electronic controls within the furnace, and with more moving parts you have more things that can go wrong and therefore additional potential for breakdowns. However, I’m not aware of any substantial reliability issues that would cause me to shy away from purchasing a high-efficiency unit.