We recently rated folding and nonfolding treadmills that provided workouts to challenge the avid runner or accommodate the casual walker. The 18 models cost $1,000 to $3,500, a large enough outlay to make an in-store tryout essential. Some featured TVs and fans.

Spend $3,000 or so on a nonfolding treadmill and you’ll likely get more horsepower, a thicker deck, sturdier construction, better hardware and a longer warranty than in a cheaper machine. (A folding model with similar specs will cost about half as much.)

If walking is your exercise, any of the treadmills we tested should be fine. But some stood out from the pack.

Among nonfolding models, we liked the Vision Fitness T9500 Deluxe ($2,000) and the Vision Fitness T9200 Simple (costing $1,300, it’s a CR Best Buy). Both measuring 52 inches long by 20 inches wide, they are relatively compact, as treadmills go. However, the T9200 Simple lacks a chest-strap heart-rate monitor.

Top-rated among all folding treadmills, the Bowflex 7-Series ($1,500) performed better than similar models costing hundreds more. A CR Best Buy, it measures 60 inches long by 20 inches wide when unfolded – one of the longest in our lineup. Shorter – and narrower – models we liked were the Horizon Fitness Performance Series PST8 ($1,600; measuring 57 by 19 inches) and the Keys Fitness Ironman 320t ($1,200; 54 by 19).

If your workout space is limited, consider the LifeSpan TR2000HR ($1,300). At just 51 inches long by 18 inches wide unfurled, this folding model is bit small for running, but might fit into places that can’t accommodate a larger machine. Note, though, that it lacks a chest-strap heart-rate monitor and was one of our lower-scoring treadmills.

Highest scoring of all the treadmills we tested, the nonfolding Landice L7 Series Pro Sports Trainer ($3,000) is well designed and sturdy, although it lacks a chest-strap heart-rate monitor. It measures 58 inches long by 20 inches wide.

Other excellent choices for avid runners are the NordicTrack S3000 ($3,500; 60 by 20), the SportsArt TR32 ($3,500; 60 by 22) and the True PS300 ($2,400; 60 by 21). The NordicTrack, which has “quick” keys that simplify setting the speed; the SportsArt has adjustable cushioning, while the True is the best value.

The NordicTrack Elite 3200 has an LCD TV in its control panel. This folding model (57 inches long by 20 inches wide, when unfurled) costs $1,900, not including cable or satellite hookup. Several models, meanwhile, have cooling fans built into their consoles, but we’ve found they’re not as effective as a floor fan.

A couple of machines we tested had manufacturing defects – a quality-control issue that keeps popping up in our treadmill tests.

One, the nonfolding True PS300, did not run at all when we got it. That problem was traced to a faulty circuit board, which was replaced under warranty. More troubling was the Horizon Fitness Elite CST4.6, a folding model that – at $1,000 – was the least expensive treadmill in our lineup. Its 53-by-19 deck was damaged during our durability testing, which is designed to simulate a year’s worth of regular use. A second sample of the Elite CST4.6 we evaluated also showed damage during testing.