An all too common mistake is to presume that there is a constant location (on your feet)where the weight should be on top of.
Even in Tango, this is not quite true.
Your weight will shift to accomodate the creation of seamless, jerkless movement.
(This is a technique that is currently being argued over ad-nauseam in this forum BTW).
Anyway, weight shift, particularly in Tango, should be studied as part of a process and not as a constant position.
Lastly, the Tango is more exhausting because you expend energy in starting AND stopping the movement.
Whereas, the other 4 simply require light use of existing momentum--making it comparatively effortless once the movement is started.
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