This model is in “end of life” status, So I couldn’t recommend that anyone get it at this time. It’s very hard to get any ADT support for it, it’s almost impossible to find the individual sensors for purchase, and it has not been getting updates at the same rate as the other smartthings models.
ADT instead purchased a different company (Lifeshield), and that has now become their DIY no contract option, which is now called “ADT blue“
You can See discussion of that process from this forum in the following thread:
If you want both zigbee and Z wave in a DIY security system with optional monitoring, I would look at abode:
I think it has the best mix of cameras, Z wave, and zigbee in a low-cost system right now.
Ring Security and ADT Blue are also possible candidates, although the home automation component in those is not as strong as in Abode.