Con's: Super bummed that for $1160 they couldn't include an internal ANT+ transponder and Heart Rate strap(sub $100 package). The foot straps are crap! Within the first 1000m of moderate rowing they loosen to the point of being able to pull foot out on Recovery of stroke(Yes, even with ball of foot down). I really wish the WaterCoach F.I.T. software for the S4 Monitor was macOS compatible. It'd be nice to able to customer program workouts on my MacBook Pro or iMac.
Outside of resistance type, we found the number-one arbiter of ride feel to be cord quality. Water ergometers tend to employ nylon cords, while air ergometers feature metal chains — a durability factor we anticipated would result in our favoring air. But while all three water rowers aced our expectation of smooth, high-tension strokes, perfecting the chain seems to be more difficult: Some tug with just a slight rumble, others feature bouncy, grinding chains that are incredibly loud, something akin to angry snoring. As for nylon, the best wind and unwind like elastic silk — no slack, no sound, no catching, just perfectly even tension throughout the stroke.