"next to the fact that they are tied to their own ecosystem of course"
That's not entirely true. Initially it was the case, but I can own an Android Wear watch and use an iOS device to drive it:
I do not believe the opposite is true.
I actually have both--a first-gen Apple Watch and an LG Watch Urbane--and prefer the Apple Watch, but I am firmly in the Apple ecosystem, so it works better with that. I do like the "look" of the Urbane, though, as it feels more like a traditional watch. A bit more objectively, I have found that battery life is better with the Apple Watch, it is more stable, and does a better job of measuring the biometric data. I've had the Urbane crash a few times, and it is basically useless until you re-pair it. Not the case with the Apple Watch.
I've had the Urbane in storage for a year, now, but I am going to try Wear 2 to see if it has improved.