The reason I'm writing now, two years after purchase, is, I broke one of the wheels. I proceeded to order the wrong replacement, so I emailed them pictures to ask for the right parts. They wrote back asking for the serial number to get the right unit AND to see if it was under warranty. (Hadn't even occurred to me.) Turns out it was, they're sending me the wheels, they're refunding me for the wrong part, AND included a link for the Puri-Tabs which I didn't know they provide for the life of the ROWER! They're also replacing all eight wheels even though there's only one broken one.
The rowing machine itself is unlike any other on the market with its patented water filled flywheel. It is hard to exactly copy the action of a scull on the water, but the mechanics of the flywheel spinning in water comes in a close second on dry land. The fact that the water is 800 times denser than air means that there is no need for any extra resistance or dampening that you will find in normal air rowers. The faster you pull, the more resistance is generated giving it infinite variability. However, if you want to be able to practice rowing with a faster stroke, you will have to reduce the amount of water in the tank unlike an air rower where you just have to adjust the baffle.
Both the air rower and water rower machines are very popular choices of rowing equipment, particularly the former type. They have been around in the 80s, and many consumers and those that have tried them in gyms consider the equipment to be the best type ever. These air resistance equipment, often regarded as Ergometers, is the standard base model for indoor rowing sport.
Storage is also a plus point for the Waterrower series as they are all designed to stand upright with the tank acting as ballast for stability. In this position they only take up around two square feet. Again, great if you are planning on training in the living room. However, if you have small children, I would advise fixing the top to the wall with a hook and strap.
I loathe exercise. Will do almost anything to avoid it, like holding down a couch or going to wash a car. But the time came to find something that I could do that would get me into regular exercise and make the most of the time. After researching, I found that rowing was almost universally lauded as a great full body workout that does not abuse your joints, and requires only a minimal time commitment. After searching and researching , the Water Rower consistently came out at the top of the pile. So I spent the big bucks and ordered one.
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.
Although some rowing machines are made of space-age, super-sweat-resistant metals, you still want to wipe off the equipment after a sweaty workout.  These machines are usually constructed with a lot of various materials and salty sweat can be very corrosive.  Keeping your rowing machine clean can go a long way toward extending its life, and its appearance.
The Water Rower comes partly preassembled in two large boxes. The assembly instructions are reasonably good, and as long as you take your time and follow them carefully (read all the text) it takes about 45 minutes from opening the first box to trying it out. I bought bottles of distilled water to fill it, which made it easy to fill using the included funnel & hose.