@JohnR has a zigbee based chicken coop door controller. 
ZigBee based Chicken Coop Door
Zigbee devices have noticeably smaller antennas than zwave, somewhat better battery life, and tend to operate a bit better in rain, so you’ll find many of the outdoor devices are zigbee, not zwave. But both work well with SmartThings.
On the other hand, Zwave doesn’t overlap with WiFi. So personally I tend towards Zwave inside the house, zigbee for the yard, but it just depends on the specific device needed.
If you’re looking at zigbee devices, look for the Zigbee Home Automation profile, as that’s what ST using. They’ve added some elements of Zigbee Home Automation Pro as well, although I don’t think all yet.