Armstrong A97MV or the Ion 98 temp star gas furnace. What company hi harder to deal with under a warranty repair and of these units is their any week points that you know of? what one would you get?
I think these brands can be purchased by anyone so you have to pick a good company to install it. It's the installing company that could give you warranty issues, not the manufacturer.
The Tempstar is sightly more efficient but both are so similar your utility bills would not notice.
You also want to make sure they sell you the proper thermostat to take advantage of all the features.