Originally Posted by RChung

Yup. The Pro was designed to be very realistic in capturing the acceleration component and aero drag component of cycling, and ignored the slope component: for this, it has a big flywheel and a (shrouded) wind turbine, and they work very well, very realistically. That's why they're popular for track athletes, who don't usually worry about slope. Most smart bikes and trainers really really wanted to capture the slope component so they could simulate climbing and they do this with electronically controlled load generators rather than big flywheels and propellers. Flywheels and turbines are a "passive" way to control load, while smart load generators are an "active" way to control load. However, the load generators in smart bikes and trainers don't tend to mimic the change in kinetic energy very well. Different audiences, different purposes, so different designs.

I've occasionally wondered whether the dearth of sprint segments in the original Watopia but lots of climbs had to do with the difficulty in getting the accelerations right.

(Anecdotally, I've heard some recent grumblings about Stages' customer support, both for their cranks and their SB20 smart bike. I have no first hand experience with either).