The main difference between these two motors is the pedal assist. The progressive surge of power you get in sport mode really does make you feel like the bionic man! The motor feels more like an extension to your own cycling abilities.
The pedal assist system (PAS) on the Bafang motor acts like an on/off switch. As soon as the pedals rotate a few degrees, the motor kicks in.
However, Tsdz2 can add throttle as bafang now. So I recommend Tsdz2, it can bring you 2 method feelings of riding.