* 800-900 MHz only
* every z-wave device works with every z-wave controller
* z-wave signals travel further
* z-wave requires aes-128
* power consumption is roughly the same as zigbee
* z-wave is an open standard contrary to what you say
Oh and HDMI as well. I spent at least a year of my life working out interoperability issues for a major DVR mfg. If only HDMI certification had been controlled by a single company...
Not all standards are made like utf8, ie commissioned last minute by a committee, written by two guy over the weekend and adopted by committee the week after. Then used by everyone for decades with little to no changes.
Still overall a shit experience.