The google takeover of Nest forced me to switch my thermostats to ecobee, which work fine but with a worse interface. I’ve been using August locks for a long time, and they work fine now (the original version was iffy). Recently i replaced 8 light switches with various leviton dimmers and switches. I also installed a motion sensor in the garage. And I use 6 Ring cameras bridged to homekit with homebridge. Then add in several plug-in smart outlets, including three in the back yard to control a whole bunch of lighting that I just installed (after adding outlets to my backyard - big project the last couple weeks). It’s all controlled by home kit automations - my kid turns on the light in her bathroom, that means the lights in her room shut off, etc. So far it works great.
That said, what Moment will do is greatly expand the selection of devices that I can add to the ecosystem. In-wall outlets and switches have few choices in homekit right now. Door locks, too - really it’s Level or August, unless you want to go with something like the full lock replacements from Yale. In many categories of smart devices there is only one or two homekit choices, and often these don‘t work for me (e.g. they are battery operated, and I want hard wired or plug-in). Particularly on the sensor side, Homekit choices are pretty weak. For example, there really is only one outdoor homekit secure video camera. Two, if you don’t mind drilling a hole through a wall to run a wire, because though the camera is outdoor-rated, the wire connector and power supply are not.