Iris recently announced no more support for their system. I am trying to use a Smartthings hub to replace what I had. I have the v3 hub, Neo Door contacts and Arlo cameras. (Had Iris door contacts because I was told they would work, but version 1 does not so had to buy Neo). Does this hub make any notification sounds? I would like it to chime like I could do with Iris when a door opened. But, I see no way to do that. I would also like to be able to set an alarm and have it notify me if any door opens. Do I really need the ADT hub? I really don’t understand the difference between these and I can’t figure out how to do much with this hub. Not even sure if I can return this hub. I wish Iris would have just left all as it was. What a pain! Any advice appreciated!!
Welcome! If you look at the thread title above your first post you will now see a little tag that says “afterIris”
Tap on that and you will see the list of discussion threads from other Iris refugees and you should find some of those of interest. 
As far as the ADT model hub versus the V3, see the following thread (the thread title is a clickable link)
Also, I’m not sure what the “Neo” sensors are. Do you have a link? Are they the Neo Coolcam Devices, and if so, which model?
Neo Door/Window Sensor. I bought them on Amazon and do have them connected to the Smartthings hub that I have. I have an automation that sends a notification to my phone if one is opened and that works, but I need more. I will check out the AfterIris stuff - that is exactly what I have been searching for. Thanks!!
Ok, first rule of home automation: The model number matters. 
As you noticed with your first generation Iris sensors. They don’t work with SmartThings, most of the second generation do.
Anyway, for some complicated reasons the SZneo zwave devices are certified under the coolcam name. But the company also makes devices on some other protocols, including Wi-Fi, which is why the model number matters. It should be on the device itself, sometimes on a label inside the battery compartment.
I set up a door chime mode with the Dome siren but ended up not using it since with Alexa I can monitor the contacts and have Alexa say things like “Front Door”, “Back Door”, etc. which I like a lot better. I used to use the Iris keypad for the chime.
You have a boatload of issues here. Let’s start off with Welcome to SmartThings fellow Iris refugee!
I too had been orphaned by Iris, and have moved to SmartThings… However I chose a different SmartThings path, I can address that path.
Do you really need the ADT hub? Nope. But do you want a keypad, and at least presently less expensive sensors to replace your Iris stuff then yes…
If you have been actively using your Iris system, you knew on January 31 that March 31 they would shut us down, so I guess your definition of recently is all relative, but if you also read the announcement, they would reimburse for non transferrable hardware, meaning your hub, keypad, and pretty much anything first gen Iris. That’s how I was able to spring for SmartThings.
My ADT SmartThings Security hub does indeed have configurable notifications for each sensor if you chose to do so. My front and back doors for example tell me when they are open through the hub even if the alarm isn’t armed.
Lowes while doing right by consumers by buying out Iris stuff that won’t transfer, really never invested the time, or financial resources into allowing Iris to flourish. And given that it was “house branded” just like Wink @ Home Depot, you’re kind of stuck with a by design limited market. Not a great idea for something like Home Automation and security. Don’t get me wrong. I loved Iris, but I can certainly see where it failied business wise…
And lastly, while Iris is dead, if you can hang on a bit, there is a team working on getting the now open sourced code to work and have the system revived as Arcus Smart Home.
Now disclaimer time, I like tinkering with this sort of stuff. Fiddling around with things getting them to work might just get on your nerves… But I have found the following so far.
#1. SmartThings on my ADT hub at least, works WAY faster than Iris ever thought of.
#2. Device compatibility is WAY better with SmartThings than Iris. However…
#2a. To get that device compatibility you hvae to install and configure custom applications and device type handlers, somewhat like installing a driver in Windows, but from source code… That can be intimidating, and the documentation isn’t super user friendly, but it can be fun…
#3. The ADT hub, everything, mostly, runs locally instead of over the cloud. I have had instances where Iris wasn’t available due to cloud problems, your regular ST hub will be the same way, ADT runs things local so that avoids some of those problems, but my Ring cameras make up for that, Ring cloud seems to have connection problems about once a week so far. Knowing this, I’d steer clear of Ring for security sensors etc…
Do you need the ADT smartthings hub. Maybe or maybe not. Where the ADT Hub shines is the fact it is a full blown security system and home automation in one. That is significant in that it has cellular backup for monitoring, a proper keypad, entry and exit point, text to speech/chimes for sensors, and all the flexibility of Smartthings. The one big issue people talk about is thay only the dual branded sensors can be used with certain security system functions like monitored alerts and triggering the internal alarm. If you want the best alarm system with Smartthings built in it is generally your best option. With that said if you aren’t focused on the security aspect the regular hub is likely fine for what you want to do.
I would suggest the ADT Hub simply because why not, price wise it is hard to beat for what it does regardless of if you use the security aspect fully. You dont give up any functionality by having it.