Different people have different requirements for peace of mind. So different solutions will work for them.
My own personal minimum requirements are:
One) that the system work when both power and Internet are down, including sending notifications
Two) that those notifications include going to a professionally monitored call center that is authorized to call both fire and police response in my area
Three) that those notifications go by cellular, not Internet
SmartThings, whether it’s the V1 hub or the V2, does not meet any of these requirements. So I pay a minimal monthly fee, less than 20 bucks, for a separate service to get all of these. I like smart things, and use it for convenience home automation, It just doesn’t happen to meet my needs for a home security system.
Other people just can’t stand to pay a monthly fee, or feel it’s really important to have all their controls combined into one app, so they will make other choices.
SECURITY FEATURES THAT SMARTTHINGS DOESN’T HAVE
With the V2 app (works with either generation hub), SmartThings released a new feature called “smart home monitor” which is intended to work more like a security system.
The problem is, as it currently stands now, it really looks more like a proof of concept then an actual working system. A few of the issues:
A) It doesn’t monitor your doors to see if they’re locked or unlocked. It monitors the doors to see if they’re closed or open, but that’s not the same thing. This seems a strange omission for a security system. I expect they will add it later, and there are some workarounds, but it’s not there now.
B) You can now again add a second user if you have an android or iOS phone, but not a Windows phone. The feature is complex, and not necessarily what you would expect unless you’re just trying to set up two family members with identical permissions. Read the official information carefully to make sure it will meet your needs.
C) there is no delay option for either arming or disarming. Again an odd omission. Most alarm systems let you turn on the armed status, and then give you 30 seconds to get out of the house before the alarms will trigger. Or they give you 30 seconds or so at the Front door to disarm the system before the alarms go off. Smart home monitor does neither. You have to be outside of the detection zone. This will probably change in the future, but again for now it just feels more like a prototype than a working system.
D) the “goodbye” routine is broken. This is another one that used to work. And that they say they’re working on to fix. But right now if you set up the officially provided goodbye routine to change the alarm status automatically when you leave the house, it doesn’t happen. You have to manually remember to change it. (The "I’m home "routine does work.) updated 31 October 2015: some users are reporting this is now fixed, but not all. It looks like this will work if the notification is set for less than 10 minutes but not if it’s set for 10 minutes or more.
E) there is no security keypad on the official “works with SmartThings” device list. They are working on one, but it’s not yet available. Many people like to have a keypad, because it’s easy for children, dog walkers, temporary visitors, etc to use without having to authorize each one with a smartphone app. And of course a wall mounted keypad can’t get lost. There are a couple of key fobs that work, but those don’t solve all the same use cases.
F) deleting a user doesn’t force a log out.. You can delete a secondary user after you have added them. However, this does not force them to logout. Although they will no longer be able to control devices, they will continue to be able to see the status of devices, including presence sensors indicating who is home and away, and lights which might indicate exactly which rooms are occupied, until they themselves logout of the SmartThings mobile app on their own device.
G) the concept of master account and sub-accounts gives access to an entire location at a time. Basically once someone has access to the account for a location, they have access to all account features at that location. This can be particularly problematic for landlords, but can also be an issue with parents and teens, etc.
H) there is no purpose-built glass break monitor device that currently works with smartthings. As you mentioned, Iris does have one. So do a number of other security systems. Smartthings does not yet.
I) Video clips are stored in the cloud, but not downloadable. this mean you would have to give someone access to your account to view a clip. There’s no way to download it and then forward it to the police department or an insurance company. SmartThings says they’re working on expanding these features. Again, it just looks like a proof of concept beginning, not really comparable to the competition.
https://support.smartthings.com/hc/en-us/articles/205380804-Video-integration-with-Hub-v2-FAQ
J) No integration with a security camera’s built in motion sensor for most models, even the officially-supported Samsung these days many security cameras have their own built-in motion sensors. Some security systems, although not all, allow you to trigger other events like a light or a siren from the camera’s motion sensor going off. As of this writing, the SmartThings smart home monitor could start the camera (if it was one of the few approved models) if a separate motion sensor on your network went off, but it did not have access to the motion sensor events built into the camera itself.
K) Most notifications work, but some are broken. in general, SmartThings has very good notification options, allowing you to use push notifications, text notifications, or via IFTTT, email notifications. SmartThings also has an excellent choice of sensors, not just the usual open/close sensors and motion sensors, but also moisture sensors, light sensors, and tilt sensors. (But, as mentioned above, no glass break sensors at the present time.)
However, with the new V2 app released in September 2015, custom Smart Home Monitor notifications that use a time setting may not work. Support has been able to replicate this, but not fixed it yet. As an example, I have an alert if a linen closet is left open for more than two minutes because there are toxic substances there. It just never sends. I could get an alert if I just wanted to know if it was open, but not if it was left open for a specific time period.
L) SmartThings will occasionally push out updates without notice that will take your system offline for anywhere from a few minutes to several hours, typically in the middle of the night. Sometimes these will require a manual reboot of your hub afterwards.
Even if you do get pre-notification of one of the system updates, there’s no way to postpone it. This is not typical of security systems. It could also be awkward if you are using the system as a security monitor for someplace other than your primary residence and physical reset of the hub or devices is required after the update to bring everything back online.
So while there definitely are people using SmartThings as a very cheap security system, and it may be better than having nothing, check each feature that is important to you very carefully, and make no assumptions about what it offers.
Competitors
In particular, you might want to compare it to some of the other DIY security Systems in the low cost range that have primarily security features rather than home automation. This would include Scout, simplisafe, FrontPoint, Abode, etc. Some of these have options where you don’t have contracts, but you can just pay to turn on professional monitoring for a month, or even a week if you’re going to be out of town and monitor it yourself the rest of the time . Those are interesting plans.
Again, though, make no assumptions about what features the system actually has. Some of those that do have “professional monitoring” can only call the Police Department, not fire. Since my own primary concern is fire safety, that made a big difference to me.
SmartAlarm by @geko
People who do use SmartThings as a home security system typically do use the community created “smart alarm” smartapp rather than the officially provided smart home monitor" smartapp. Smart alarm includes delays, zone monitoring, lock monitoring, and some other features missing from the official smart home monitor smartapp.
All of the above was as of October 10, 2015. I’m sure SmartThings will be adding more features to smart home monitor over time. As I said, right now it feels mostly like a proof of concept to me. Each individual screen looks fine, but when you try to walk through the details of an actual use case, you may find quite a few things missing.
JMO, others may find that smart home monitor is exactly what they need. Everybody’s priorities and preferences are different.
More information on the community-created SmartAlarm smartapp
( The following is a clickable link. You will find most of the people who use smart alarm in that topic.)
Using Custom Code
Community-created code actually doesn’t run on the hub or on your phone. Instead, you copy and paste it into your account in the SmartThings “cloud” where it runs on servers that your hub will access over the Internet. It’s not that difficult, and one of the absolute best things about smart things is the helpfulness of the forum community. There will be lots of people to help you if you get stuck anywhere.