The Concept2 Model D is the ultra-popular air rower that you’ll see at most gyms. It is one of the best home indoor rowers you can buy period. Expertly constructed and ergonomically unequaled, this rowing machine looks great and rows smoothly without so much as a jarring catch. As an air rower, the Concept2 employs air baffles to create the resistance. A nickel-plated chain pulls the flywheel and you get your workout by pulling against the increasingly higher air pressure that the fan is creating.
The advantages with air rowers is that there is smooth action; there is only small wear and tear to its mechanism; its automatic feature adjusts according to your rate of strokes; and there is a wide range of the resistance readily available in replicating the feel of rowing through the waters. The only disadvantage of this machine is that it tends to be noise indoors.
The resistance of your rowing machine impacts how it moves. Select from hydraulic and magnetic rowing resistance. Hydraulic rowers are typically more compact in size, while magnetic machines make little noise as they operate. Details like easy-to-reach tension knobs or buttons allow you to increase or decrease the intensity of your resistance as you train.
If you're looking at a WaterRower, you're probably also considering the Concept2. They're both great machines, but which you choose depends on your needs. I think the WaterRower is ideal for most people, but not everyone. The WaterRower has a number of advantages vs the Concept 2 - it is quieter, the mechanism up front is lower profile, it has a comfortable seat, it is much better looking, it's easier to stand up when you're not rowing and it's just ... zen-like. There is something about the smoothness of the WaterRower that makes it a joy to use, and because it's quiet you can easily stream your favorite binge-series without cranking the volume too high.