When we check in where?
I assume he is UAE ACC but to be honest you should really do so any time you are not flying "normal" or you flight planned speed. Of course the definition of normal will vary depending on who you talk to.
I have definitely noticed that the holds are not as full recently, especially during the peak EK arrival times so I think it must be helping. I also think that it must help EK ops with scheduling too in that they ought to be able to see where they have potential bottle necks and make adjustments to help with late runners or more important transit flights.
No doubt it would be nice if all airlines used it and there are systems out there that can do that. Of course getting something like that in place around here is a little challenging.
The main problem with the EK only system is that the ability to gain time is less than the ability to lose it as I understand it. The UAE ACC AMAN system looks only a certain distance out as has been mentioned so in slowing down often all you are doing is letting a few non EK flights in ahead.