For a third option, you can look to hydraulic machines, which use pistons to generate resistance. Hydraulic rowers are quiet, and they also tend to be smaller and cheaper than other kinds of rowing machines, but you won’t get the same smooth rowing feel, or the consistency of resistance, that you would get with an air or water rower. What's more, reviewer after reviewer has found them unreliable and high-maintenance.
How good is the display? What data does it show you? Tracking your progress is an important part of losing weight, improving your fitness, or striving towards almost any goal. That means that when choosing a rowing machine, you shouldn't forget to think about its display. You want a machine that will tell you - clearly and accurately - how many calories you've burned, how long you've worked out, your strokes per minute, and so on. Many rowing machines come with a heart rate monitor, too. Even if you have your own wearable fitness tracker, don't underestimate the value of being able to export data from your rowing machine.
Outside of resistance type, we found the number-one arbiter of ride feel to be cord quality. Water ergometers tend to employ nylon cords, while air ergometers feature metal chains — a durability factor we anticipated would result in our favoring air. But while all three water rowers aced our expectation of smooth, high-tension strokes, perfecting the chain seems to be more difficult: Some tug with just a slight rumble, others feature bouncy, grinding chains that are incredibly loud, something akin to angry snoring. As for nylon, the best wind and unwind like elastic silk — no slack, no sound, no catching, just perfectly even tension throughout the stroke.