If you want context…
Programmers tend to think in terms of the total number of transactions completed.
However, consumer products, including residential security systems, are usually evaluated on the basis of “maintenance free operating period.” So let’s say you have a thermostat which completes about 150 internal transactions per day. If it was wrong once a day, a programmer might think that was 99.3% uptime. But from a consumer product standpoint, it’s zero reliability, because it fails every single day.
My own minimum requirement for an inexpensive intrusion alert security system is six months MFOP. That’s not great, but it would be good enough if I liked everything else about the system and the price was right. It would also not be good enough for a fire detection system, because I expect much higher reliability from those.
Anyway, since November 2015, I have yet to go 10 days without SmartThings requiring some kind of hands on maintenance. It might just be popping the battery in a sensor; it might just be opening the app, navigating to a rule, and resaving it; it might just be something that was glitchy for a few hours. But it’s nowhere close to my six-month minimum.
You should also be aware that as a cloud-based system SmartThings can and does push out updates which you can neither refuse nor delay, and these can take your system off-line for anywhere from a few minutes to several hours. I do count these against MFOP because while we sometimes, but not always, get a couple days advance notice, it’s nothing like scheduled maintenance where you know at the time of purchase how often the system will be unavailable. And quite often when the system does come back online various individual devices are either temporarily unavailable or need to be physically reset.
Also note that will some bits of the system do work without Internet, most don’t. Just as an example, if the Internet is not available you will not be able to use the phone app for anything as it requires the Internet to communicate with the hub even if the phone is on your home Wi-Fi. Also, there is literally no way to either arm or disarm the Security features if the SmartThings cloud is not available. So if you have it set it up so that if the Front door is opened a siren goes off even if the SmartThings cloud is not available, you can do that, but you won’t be able to turn off that feature without the cloud.
(BTW, that particular community member has since moved his household’s security functions to a different system.)
I like SmartThings for convenience notifications like knowing that the guestroom window was open when rain is expected and the guest is away, and it does these better than any other system I’ve found at a similar price point. But I use a completely different system for security, one which can operate without the Internet and which has an MFOP of well over six months.
But again, different people have different requirements, and as long as you’re not installing it at a second location it’s easy to test for yourself. Put it in and log all the maintenance requirements for the first three weeks. Then you can decide if it meets your requirements, or return it. Don’t just rely on your memory, though. Actually log every time you have to physically do something to keep the system running.
The stability issues with SmartThings aren’t subtle. You’ll generally know within a few weeks whether it’s something that bothers you or not.