Are there any in serious use anywhere? In the UK we trialled two types but both were rejected for a number of reasons. In the end, a well-trained, experienced controller could equal and usually beat the performance of the system. There were a number of safety aspects which gave rise to concern too.
One problem was the additional workload imposed on the controller. Each system we trialled required input and that added to the control task. The Final Director task at a busy airport requires a very high degree of concentration and to disturb this process by introducing the distraction of operating the sequencing tool defeated the object.