Function plays a large role in defining good design. When designers look at an object, they don't just consider its aesthetic appearance; they should also challenge it to be more versatile, to respond to the user's need, or to achieve its purpose more elegantly. Good design has the capacity to solve problems that sometimes we didn't even know we had. This is one of the ways design touches and enriches our everyday life.
On theme with C2’s interchangeability, models D or E are essentially the same machine. When we talk about one we’re talking about both. The Concept 2 E is just 8 pounds heavier but is made out of stronger stuff all around — what’s plastic on the model D is aluminium on the model E, and what’s aluminum on the model D is welded steel on the model E. The only noticeable variations are seat height and display position.
After reading so many fantastic reviews I purchased the Classic model. Before I write what I think are the negative aspects I'll say that it gives a great workout! That is pretty obvious and I don't think that part is arguable. The disappointment began while unpacking. The wood parts were wrapped fairly well and did not have damage but there were several scratches that I had to sand out and re-oil. It appears that they were there before shipping. Putting it together would have been fast and easy- except 2 of the bolts were bent at about 15 degrees and would not fit. I had to wrap with tape and bend with vice grips. After getting it all together the rower worked well for about a week. I started to notice an annoying kind of popping sound from the left rail as the wheels rolled over on each stroke and recovery. It seems the plastic that the wheels ride on is not flat or adhered well to the rail. It isn't very loud but I can hear it well and it gets my attention, spoiling the nice sound of the water. Really disturbing. Support at WaterRower would like a video of the issue. Seems like an obvious issue and could swap out with a rail that is good instead of me trying to make a video of this small sound while moving the seat back and forth. For a $1500 machine the quality control- or lack of it is disturbing. Having to jump through a bunch of hoops because they are too cheap to just send a part is even more so. Perhaps I am being difficult but it is upsetting to have something touted as so great but put together like a $200 piece of junk. Another complaint would be the lack of any back lighting on the monitor. Really cannot see it if the lights are low. Being able to remove the monitor to attach to a PC wouldn't hurt either. While it gives a good workout the rower really suffers from poor manufacturing.

Rowing has long been recognized as the perfect aerobic pursuit, with naturally smooth and flowing movements that don't tax the joints but do boost the heart rate. Now you can take your rowing experience to the next level with the WaterRower Natural rowing machine. Using the same principles that govern the dynamics of a boat in water, the WaterRower Natural is outfitted with a "water flywheel" that consists of two paddles in an enclosed tank of water that provide smooth, quiet resistance, just like the paddles in an actual body of water. As a result, the machine has no moving parts that can wear out over time (even the recoil belt and pulleys don't require lubricating or maintaining). More significantly, the water tank and flywheel create a self-regulating resistance system that eliminates the need for a motor. As with real rowing, when you paddle faster, the increased drag provides more resistance. When you paddle slower, the resistance is less intense. The only limit to how fast you can row is your strength and your ability to overcome drag. And unlike conventional rowing machines, which tend to be jerky and jarring, the WaterRower Natural is remarkably smooth and fluid.