There is no such thing like 'true ECN' available with any mt4 broker.
The few ones which are connected to some ECN feed doing it by bridges, which slows down the execution speed dramatically, hence worthless for mdp.
No matter what mt4 brokers claim themself to be, they all remain bucketshop market makers in the end.
When the client wins they lose. That's why mdp performance is going downhill. They using now all dirty tricks to defend themself. Trade execution slowing down is their best weapon on this. I'm observing this on all so called 'STP/ECN' brokers. Scambags.