There have been many discussions of reliability and SmartThings really, almost from the beginning.
Personally, I have never put anything On SmartThings except convenience use cases where I had an immediate plan B if it failed. I have a completely separate, and very reliable, security system that I’ve used for years and I’m very happy with. But I’m willing to pay a monthly fee, and many people are not.
As far as alternative home automation systems, again, much discussed in the forums.
If you can afford to pay $10,000 a room, there are some great systems out there, very reliable, local processing, tie everything together. That’s considerably outside of my budget however as it is for many people here.
If you’re looking at the low-end systems, where SmartThings is priced right now, you’re probably looking at a budget of $200-$500 room. And not every room in the house. In that price range, there is no one perfect system yet. Everything has pros and cons.
Staples connect made reliability the number one priority from the beginning, but they got that reliability by throwing out many features that other systems consider essential. There’s no there’s no IFT TT, there’s no voice control. No Geo fencing. A very limited choice of devices, and most of those most expensive in their groups. But if you just want something that turns the lights on on the schedule and opens the curtains and works every day, it’s a good choice.
There are also several excellent security systems under $2000 that are reliable and have a monthly fees of $20 a month or less. But they don’t typically tie into your other home automation, which is how they get their reliability. Some do have an IFTTT channel which gives you some additional notification options. But they don’t let you fooling around with schedules for Halloween decorations mess up your intruder alerts. Again, personally I’m fine with having a separate system for security monitoring, but for some people that’s a dealbreaker.
Again, search the forums for any other competitor that you’re interested in and you’ll find a lot of discussion.
My own expectations has been that by the summer of 2016 there will be several reliable plug-and-play systems that fit my own needs and budget. HomeKit/Insteon will clearly be one. Something based on nest will be another. My expectation is that SmartThings May be a third, but obviously they’re going to have to make a lot of improvements to get there. I’ll definitely look at them as a potential candidate in late spring.
For right now, you can put together a very nice, very inexpensive, very reliable system just for lights based on Phillips hue and Echo and then add other things later. But I know most people don’t want to wait.
I still don’t personally expect to put security on to that system but I have my own requirements for security.
Different people will have different priorities and come up with different answers.
You might find the following conversations of interest.
The first one is specific to security.
The second one is my own project report on what I did for my phase 1 and what happened.