Yeah, I didn't get specific furnace models out of the articles. I was trying to decide between single-stage, two-stage, and many-stage designs. It turns out that the installers' claims about efficiency are bogus. Once you realize that you need the same number of BTUs regardless about how they're distributed, it's obvious. It's true that it might be more pleasant to have a little heat and a low fan constantly, rather than a blast periodically. In my opinion that's not worth the difference in upfront cost, increased maintenance cost, and reduced reliability.