This is a cross-post from my post in a poll on the General forum that may be of interest to those considering Hubitat...
The shutdown got me off my feet and over to Hubitat and Ring Alarm. I'm using Hubitat as the main hub with a relay triggering a single contact sensor on the Ring Alarm for its professional monitoring service. I've spent a lot more time on the migration than I wanted but everything appears to be running well and I now have the flexibility to implement rules and automations that were never possible with Iris. I have been able to take over every non-V1 device over to Hubitat::
Iris v2 motion sensors
Iris v2 contact sensors
Iris v2 buttons
Iris v2 keypads(+)
Utilitech (Iris) sirens
Lutron Caseta switches, dimmers, and (Pico) remotes
Orbit (Iris) water valve(*)
Dome water monitor(*)
Smartthings presence sensors(*)
(+) Works with Hubitat but no longer using.
(*) Newly added post-migration.
For professional monitoring, I soldered the Qubino dry-contact relay to a single Ring Alarm contact sensor. The Ring Alarm is configured with 0-sec entry and exit delays. Hubitat manages all the entry and exit delays and when it detects a security event, it toggles the relay after the entry delay elapses to trigger the Ring Alarm. I no longer use any of the Iris keypads and now use a Pico remote to arm the alarm and a valid lock code on the Schlage lock to disarm. I also have Alexa TTS integrated into Hubitat so that there are verbal notifications:
when the alarm is armed home, armed away, and disarmed;
for the entry and exit delays;
when the garage door is opening and closed; and
when the pool water level is too high (Dome water monitor integrated into the skimmer that triggers the Orbit water valve to discharge water via the cartridge filter).
Overall, I'm extremely satisfied with this solution. Hubitat has its quirks and I found the Hub Safety Monitor (HSM) and Motion Lighting components to be poorly thought out. Much of the effort was spent on implementing HSM and Motion Lighting, discovering all the quirks and trying to address or work around them, and finally implementing the functionality I wanted using the Rule Machine (RM) instead. I should also note that a number of key integrations between Hubitat and the Nest Thermostat, Nest Protect, Ring Alarm (to sync armed home, armed away, and disarmed states), Alexa text-to-speech (TTS), and Chamberlain MyQ (garage door opener) are dependent on community-written apps and drivers made available for Hubitat and/or Smartthings.