Just cancelled Bkool resubscribed to Xert. I've never had any interest in the social aspects and virtual reality of Zwift and the rest; all I want is to do workouts. Trainer Road and Xert seem to be the best choices for workouts that modify themselves on the basis of your power and heart rate and other data as you work out. Xert is the cheaper of the two and works great at tracking changes in my fitness.