The currently available DJ tools are all really weak and make little progress. Therefore I like the innovations of Denon very much. I will probably get a Prime Go and sell my Pioneer standalone controller.
What I think needs a significant step forward is library management. Here Engine Prime is still very much in its very beginnings. With the addition of the File Relocate function (voted for the Feature Request) it would be a bit better. But with that you are just on the level of the competition.
But with the built technology of the Prime devices one could go much further. To counteract the back and forth copying of data and the problem of data loss Denon could establish a cloud service, which contains the main collection of a user including files and DB. You could access it from a computer or directly wireless with a Prime device at any time and changes would be synced directly to all clients.
Apart from the fact that such a feature would attract a lot of attention and keep users connected to the Denon Ecosystem, they could probably also make money by offering it as a Pro Service with a monthly subscription. I would definitely buy it.