Find the machine for your room
Most bad buys start with the wrong kind of machine, before the model even comes up. Three questions sort that out, then you land on a list with prices and specs side by side.
How the questions are weighted
The room decides first. A desk means a walking pad or a seated elliptical, full stop; nothing with a frame fits under a desk and stays there. A corner you fold most days points at folding and compact treadmills. A spare room or a garage opens up everything, including the heavy non-folding frames that last longest.
Use decides second. If you run, belt length and continuous horsepower trump everything and the budget filters set the floor. If you walk, incline matters more than motor and the lists get cheaper. Low-impact sends you to the elliptical guide. A heavier user sends you to the frames rated 350 lb and up, because that limit is a walking limit and running needs headroom.
Budget comes last because it mostly changes which end of a list you read. Under $500 is honest walking territory and we say so; the budget page is blunt about what two-year machines look like.