I used OpenHab2 in the past. But its quite heavy, and bulky. However it works well... What i did notice is z-wave commands where slow on the raspberry pi..

I moved to Home Assistent and i'm not moving back. I did like the more plugin-like architecture & technical design of openhab better... But that makes it bulky. Openhab feels more mature, but also has a lot more legacy... HA is just movign faster...