SmartThings is very versatile, and when it works as intended it is my absolute favorite home automation system.
However, "easy" and "reliable" it is not yet. Search the forums for "stability" and "reliability" and you will see much discussion of this. Including the following note from April from the company CEO:
Just last week there was a hub firmware update which broke the Phillips hue integration for some customers.
Engineering is aware of it and working on an emergency fix. But it seems like something of this nature happens every month or so.
Since last November, I have yet to go 10 days without an impactful SmartThings failure.
So I certainly hope the product isn't "mature" yet because it has a long way to go to reach reliability. But it's clear that the company has committed to doing that, and they have invested considerable resources including The recent hire of Amazon's director of engineering.
So my hope is that things will continue to get better. And I have heard that the Fibaro controller system was particularly unreliable, a disappointment since their end devices have been so good.
I wouldn't be surprised if SmartThings is better than the Fibaro controller. But better is still a long way from a reliable plug-and-play home automation system.