What's the preferred Thermostat Controller for Central AC and Heating?
I have a new AC/Heating system going in and would like to get the Thermostat that works with Hubitat best.
Also, The Compatible Device List has all the thermostats listed as different device types so at a glance it appears that Hubitat only has few supported devices. It would be nice if the Thermostats were labeled consistently.
Bonus Question: In a nutshell, What is the current state of the Nest integration?
There is no best... Depends on what is important to you (need humidifier support? want remote temperature sensors? Need multi-stage compressor support? Want something fancy looking?), and how you think you are going to use it in Hubitat.
Start with the "how do I want to use this in Hubitat" question first, as it will eliminate options the fastest. If all you care about is mode & setpoint adjustment, most of them can work. If you are going to use the operating mode in critical automations, cloud based might not be a great idea... Etc.
Ecobee are very popular, but while it integrates fairly well with Hubitat, the data comes from the cloud. Only you can decide how important that is to you.
GoControl zwave plus thermostats work well in Hubitat and are relatively cheap, but don't natively support remote temperature sensors or humidifiers.
Many other options...
Oh, and I refuse to buy Nest, so can't answer that one. 
Too closed source / walled garden for my tastes.
I moved from Nest to a centralite pearl. I will never go back to a cloud solution.
I found a smart thermostat was always fighting what I needed...
It's not integrated yet.. but the Venstar thermostat's look very nice and have a LOCAL API for integration...
I have OLD Ecobee thermostats. Their cloud based reporting stuff sucks if you have more than one thermostat in your house because it doesn't combine the data. However, they work well, and the ones I have can control up to 3 aux devices. I'm only controlling humidifiers with mine.
You can also use their api to pull all of your stats down to do your own analysis on it. But, no local control.
Thanks for the input. Mind telling the community which Thermostat you use and how do you use it? As for me, I need a Thermostat that's reliable, communicates with Hubitat over Zigbee or Z Wave, and makes use of all the functions of the generic thermostat drivers. I want to make use of Rule Machine with all my devices around the house that report temperature and automate the thermostat based on temp sensors around the house.
I'm leaning towards the Centralite Pearl as well. It appears that the only Thermostats that are on the compatible device list that are local and make use of default drivers are the GoControl, Centralite, and Radio models. Of those the Centralite Pearl is the only one that's easy on the eyes. Any other thoughts on its functionality and reliability?
I prefer the GoControl, because in general I prefer zwave plus.
But I also had a specific need: ability to bias the thermostat temperature programmatically - so basically I run the thermostat off of remote temperature sensors. Because of that I needed to modify the driver to do so, and it is much easier to modify zwave drivers than it is zigbee (for me).
To be honest, it works ok. I do not use the thermostat scheduler because every once in a while I get a hiccup with the thermostat where it doesn’t take the command. Being who I am, I shifted to rule machine and added checks for the command, and then repeat it if needed. I wish I had captured an instance and logged it with the Hubitat team.
Centralite went out of business not too long ago. You might want to reconsider buying a new Centralite thermostat as you'll never receive any firmware updates or support.
Take a look at the Lux KONOz thermostat. It is all local and uses Zigbee. There are a few threads about it. Just be sure to get the Zigbee version (KONOz) instead of the WiFi version (KONO).
One down side to this thermostat, it supports two stage heating, but not two stage cooling.
If your system is single stage no problem.
Thanks for the heads up. I'll probably steer clear.
Thanks for the input. I'm looking for something that will reliably take commands from Hubitat.
What does your HVAC system need? Two stage heating and cooling has been mentioned multiple times. Reliable, while important isn't as important as what your system needs. If your system is single stage, your choices are many, but if you have a 2 stage system, you need to be more careful.
It's a single stage heating and cooling system. My ultimate goal/ideal condition is to have Hubitat turn the system On/Off or change the Target Temp using the temperatures from sensors around my house. All of the motion and contact sensors I have measure temperature and I want to leverage that information. I have a Radio CT101 and a Nest. While the NEST is a gorgeous piece of hardware it doesn't play nice with HE. The CT101 is reliable but fails the WAF score on looks. The Lux KONOz is starting to look like an interesting compromise.
One down side to this thermostat, it supports two stage heating, but not two stage cooling.
If your system is single stage no problem.
Is this something they might be able to change later with a firmware update?
Unlikely as the thermostat lacks a y2 terminal...
I spent 1 week with the NEST and then replaced it with the Lux KONOz. The KONOz works great with Hubitat but the NEST was simply better. Its a better piece of hardware with a better GUI and nice features built in like usage visualizations. For me the KONOz means 1 less app to manage and 1 less tool to account for during WAF calculations. I'll be using the KONOz exclusively moving forward for these reasons.
IMPORTANT: LUX sells a "KONO" and a "KONOz" - Where the KONO is a Wi-Fi model and the KONOz is a Z Wave. Only the KONOz works with Hubitat and the only place I found that had it for sale was the Lux website.
Thank you for posting your experience transitioning from Nest to KONOz. I have been pondering that same change myself.
Do you live in an area where you run your air conditioning heavily this time of year? I am curious if you perceive a difference in 'comfort' between the two thermostats? I am finding my Nest thermostats are waiting for too large of a temperature shift before cooling the house back down. I live in coastal North Carolina, so heat and humidity are definitely a problem this time of the year.
To avoid any confusion... The KONOz is actually a Zigbee device... 
It's funny you should ask because I do. Im in Southern California and have a newborn in the house so the AC runs all day. I enjoy the KONOz a bit better than the NEST. Before removing it I also noticed that the NEST took longer to turn the AC on. My thermostat is usually set at what I believe is the edge of comfort 75 F so waiting too long meant the house was hitting 79-80 in certain parts before turning on. I just assumed that the NEST was still "learning" my routine but I guess theres more to it.