I've been looking at DD real wheel systems for a Catrike recumbent trike. I have no experience with e-assist motors but thirty years of riding road bikes. I think I want the responsive connectiveness of a torque sensor system. This got me looking at the TSDZ2. But I know the Bafang is well thought of and very popular. I was interested in the pros and cons of these two systems. I only need a 350 or 500 watt motor. I don't want to damage the trikes drive train. Is a gear senor necessary or at least wise and I assume available to connect with these systems? If the TSDZ2 has TS is a gear sensor even appropriate? I am use to shifting gears on my bikes am I likely to quickly get use to the Bafang system and not need a gear sensor? If the Bafang doesn't have a TS I assume it motors along at assist setting selected with motor watts remaining constant and increase in speed is from riders additional watts without the motor reacting to increase or decrease wattage. Is this correct? The TSDZ2 with TS at a specific assist setting will increase or decrease wattage responding to riders wattage. Is this correct? It seems to me-with no knowledge or experience-that a TS is needed to retain the feeling of riding a bike or trike versus riding a moped, scooter or motorcycle. Any input is useful. My assumptions may be off base.