I just completed my own upgrade using a Sensi Touch WiFi thermostat. I had a Honeywell programable thermostat previously and actually purchased a Honeywell T9 and the Sensi because I didn't know which would work better in my application. A couple of considerations: The Honeywell T9 allows additional sensors to give you temperature in any location within 200' of the thermostat. Additional sensors cost around $39 each, and what that gives you is control over that sensor location temperature. The downside is if that room is cool or hot compared to the main thermostat, that sensor will cause excessive heat or cooling for the remaining rooms. The sensors can be "averaged" to give you balanced control, or can be set to detect people to control whatever room you're in.
I tried the Honeywell T9 for about 2 days and didn't like it. It caused the furnace to come on when I went into a room for a short period of time (Because of the room sensor) and it really ended up running the furnace more than I wanted it to. The second consideration for me was the narrow set points for temperature range. In other words, the thermostat would call for heat, but would only heat until the temperature went bak to the set point. A 70 degree setting had the furnace start at 69 degrees and would shut down when it hit at 70 degrees exactly. There was no control on the range of temperature swing. Bottom line was I didn't care for the sensors, and the narrow range of temperature swings when calling for heat or cooling. Because of this, I switched to the Sensi WiFi Touch by Emerson. The Sensi has several selections for temperature swing, AC protection modes for short cycling, and a great app that lets you see what's going on with the furnace no matter where you are in the world.
The Sensi thermostat worked extremely well and was very easy to install. Total install time was about :15 minutes and the app you install will guide you through the process. You will need a C (common) wire for continuous power to the thermostat which is required for the WiFi connection. The thermostat has what's called Geofence which will sense your location (through the app) and turn down the heat (or raise the temp for AC) when you are outside of a 3 mile diameter from the thermostat. It will when heat up the house to the programmed temp when you return within the 3 mile diameter. I also have Amazon Alexa and you have the ability to say "Alexa, turn the heat to 68 degrees" and that will automatically be set on the thermostat. You can also control settings through your app on your phone. The app also has a neat feature telling you the furnace run time for each time and what mode. My thermostat indicated my furnace ran in the heat mode for 1 hr. 38 minutes yesterday, giving me a good idea on my home efficiency. The Sensi also has a circulation mode that will run your blower to circulate air for what ever time period you select. The lowest circulation available is 6 minutes per hour up to 100%. You can also turn that feature off if you prefer.
Both thermostats will give you local weather on the display. The Honeywell T9 is mounted vertically which left some exposed screw holes from the previous horizontally mounted thermostat. The Sensi mounting plate has built-in LED backlighting and a built in level for accurate wall placement. One final consideration: Your wireless modern has to work on 2.4G for the thermostat to work. A 5.0G modem frequency will not work with either thermostat. I've been a Honeywell customer for most of my life and I really wanted it to work well in my application. I just couldn't get past the temperature swing issue. It seems to me having the furnace cycle frequently would put more wear and tear on the furnace. I did call customer service on both thermostats, and after waiting on hold for :20 minutes, it seemed like the Honeywell representative didn't understand anything I was asking her. She just read responses from a script and was really no help at all. The Sensi help line was fantastic and the representative seemed very knowledgeable about anything I asked, with a minimal wait time when calling the help line. (Both were called mid-week at around 2:00 pm if that matters.)
Both are fine thermostats, but I wanted more control on temperature swings, and I like having the circulation mode, so the Sensi is a better fit for me. The Sensi touch Wi-Fi comes in either white or black. The Sensi Wifi app also seems to be a bit more refined, with simple and easy display with all the information in one place. Look on YouTube for some good reviews on both thermostats. Good Luck!