I think you are targeting the wrong market if you intend to build a machine.
As a cyclist, the market sweet spot to me is the ability to set a wattage on a rower and have the machine automatically adjust the resistance so that I can hit the correct wattage/hour.
On the bike, holding a steady cadence and having the machine adjust the resistance so I can hit whatever % of FTP I'm wanting is the killer feature the C2 is missing.
All the other comments referencing injuries/etc are reflective of the need to make an ERG that allows you to just say "do 25 strokes/min" and if you blow up or cant hold the pace, drop the target wattage. It's harder to hurt yourself if the machine is setting the difficulty based on your pace and putting some sane max limits in.