Here's my feedback rollup after transitioning from SmartThings/Webcore over the last 10 days or so. I'm feeling pretty positive about Hubitat which is always a good way to start a new relationship. My hub is up and running and all my devices are integrated and I have a nice presentation of information (via the dashboards).
Let's get the less positive stuff out of the way first, The process of transitioning wasn't totally painless but not all of these issues are on Hubitat. . I had problems pairing some devices with the hub sometimes taking 4-5 attempts and, worse yet, I ended up with over a half dozen ghosts. I was able to remove all but one via Zwave Details but that one required me to purchase a PC hub (I got a Zooz S2 700) and run the SiLabs Studio to remove it. I also had some issues with rule manager 5.1 instability which, honestly, might be due to me hitting the back button. In one case, I thought the Mimo2+ wasn't responding to a switch tile but it turned out to be the rule manager (back button?) issue that made me think it wasn't working. Let me say that I posted numerous times about the issues I was having and always received a timely response. Most of the time, that help enabled me to get past the problem. Only once, did I fail to resolve an issue, that was with my wife's phones geofence not showing in the app (did I find a bug?).
I was really impressed with the breadth of device support. The first thing I did once I ordered the hub was to start looking at what devices I needed to find drivers for. I needed a number of third-party drivers under SmartThings and figured I would as well with Hubitat. But it turned out that I didn't need any extra drivers. Of the devices I was most concerned with, a Remotec ZTS-500 thermostat, a Mimo2+ Signal/Relay device, and my Aeotec ZW095 Home Energy Meter Gen5, only the HEM needed an add-on driver to expose all it's attributes (the Hubitat driver worked but didn't expose all the information available from the HEM).
Coming from SmartThings and Webcore, I also had to be impressed with the Dashboard tools which really do a nice job of presenting the information you want/need. That's only tempered by the bit of learning curve with the CSS stuff and a lack of centralized information about what attributes are presented in the templates. I spent a lot of time looking for stuff like the dimmer tile components (i.e. .dimmer, .dimLevel). It would be really great to up the documentation on those things so we can do more creating and less searching.
My system is up and running really well now and I'm thinking of expanding. I mostly worked out the presence sensing (in view of the lack of geofence in the Hubitat app for my wife's LG V20) but that's about the only thing I'd like to have working better.
I have to give Hubitat a thumbs up.
Edit: I was able to use Rule Manager 5.1 to recreate my Away At Night Light Randomizer which was one of my main reasons for using Webcore. I feel I don't need Webcore any longer with Hubitats capabilities.