The Big Difference Between the Concept2 Model E & Model D:
The Model D comes with a PM3 Performance Monitor that tracks user pace, speed, distance, calories burned, etc.. The Model E comes with an enhanced PM4 Performance Monitor.
The PM4 includes the performance measuring features above, but it also can track your heart rate wirelessly (chest belt HR transmitter included).
The PM4 comes with more memory capacity, a rechargeable battery pack and the ability for machine-to-machine wireless racing. This feature is more useful to places that service multiple users. For example, gyms and fitness centers. Unless, of course, you have multiple rowers in your home.
Option: The Model D is available with the PM4 Performance Monitor for $150 more than the Model D with the PM3. You can get it here.
Some Minor Differences Between the 2 Rowers:
There are a few minor differences between the Concept2 Model D and Model E indoor rowers. For instance, paint finish, chain, monitor arm, etc. However, none of these features affect the performance or benefits of the rowing machines themselves.
They require the same about of space to use (9 feet by 4 feet), however the Model E seat is 20 inches off the floor vs 14 inches of the Model D. There is not necessarily a benefit to this – except that it can be easier to get on and off the machine.
Rowing Machine Similarities:
They both have the same 2-year product warranty (and 5-year frame warranty) and maintenance is the same. They are both designed for institutional use and therefore extremely durable.
If you are a home-user, you can get a lifetime worth of use out of this piece of fitness equipment with very little maintenance. We recommend regular lubrication of the rower chain , and a bottle of chain oil comes with each product.
They both fold up and you can break them down into 2 pieces for easy transport and storage. This video explains more about the Concept2 Model E vs Model D rowing machines:
More Information on the Concept 2 Model E Rower