For me, the speed of object is not a good choice. I have preference for performing the distance between old and new position of the object after dragging operation.
For that, you memorize in 2 variables the X and Y postion of your object with your “Object is … dragged?”
Then, you must test in a condition that dragging operation is over: in this case, you calculate again the X and Y position of the object, always in variables (new variables)
To terminate, you analyse the difference between the variables to decide if the object has effectively been moves or not.