First, let me confess that I am an IFTTT noob.
My practical difficulty with IFTTT is that it doesn’t recognize (doesn’t list) my ST devices as inputs when I work on a recipe - unless I enable them for control. I have registered the channel and I assume the OAUTH stuff is set up and that UI indicated everything was readable by default. This doesn’t appear to be the case.
I also don’t like the fact that it only accepts one input instead of multiple (e.g. every door and motion contact in the house) and takes only one action (calls or turns on lights - again, only one light - but not both actions).
Additionally, I was hoping to keep the user-driven configuration/enabling in the ST app. By having it in IFTTT instead of the ST app, nobody else in my family can enable or disable the “alarm” at night.
On a less practical level, I didn’t love the idea of exposing all of my information (ST data, in this case) to yet another service provider (though I could probably get over that if it the practical considerations were addressed).