I might sound a bit rude saying is "not a good ECS". I should have say is not performant enough
Artemis is based in Java and the C++ implementation I saw some time ago had the same sin: Components are virtual stuff, denying a lot of goodies from ECS. They also rely on using hashmaps and other containers which are really bad for cache coherence to access components.
There were more bad stuff but I can not remember. I will rephrase what I said: is not a bad engine but you could design a way better ECS engine. If you are using any virtual in components then you are not designing an optimal ECS. Virtuals of course are ok in systems.
And t-machine.org readings are good stuff. But I remember the guy from t-machine went a bit too far with ECS, last readings sounds a bit like die-hard ECS (and ECS is just a design tool!). For example I remember disliking specially its bomberman example and some articles seemt a bit vague. When I coded my own ECS I found bitsquid articles way better and very clear. If you have time to carefully read through all the ECS stuff over the internet then yes, go for everything! But my 2cts is to focus instead on better sources like the bitsquid one.
I'm sorry I can not bring strong data to support my feelings on this
BTW. @ricardo how are you planning to incorporate a pure ECS system to cocos2d-x while mantaining backwards compatibility? I mean, It would be really cool to have such a core for the engine but I'm curious on the compatibility stuff.