It's only drawback is it will not automatically sense occupied room states or provide a simple home/away button via web or phone app. It's best feature is sending an email when house temps drop below a preset temp., or when the power is out and the server is unable to connect to the thermostat. It also has a much simpler interface and programming schedule function than all the other smart thermostats currently on the market. All you need is a reliable wifi connection.
The thermostat comes default with a programmable interface, which is often useful with furnaces, as it can be setup to provide 2 stage heat, and 1 stage cooling. The Honeywell will also learns over time how long the house will take to reach temperature in a call for heat or cool, and will provide an "early-on" capability to have the house to the temp when you want it. In all cases, the common wire is required installation of Honeywell WiFi capable thermostats, so 3 wires need to be available if this is used in a heat only application, with the common wire connected to the transformer in the mechanical room. Most furnaces provide this option and have 5 wire thermostat wire pulled to the thermostat location already. I have found that a fairly easy and in-expensive retrofit if it isn't already there.
The main difference between this and the flagship Honeywell Prestige 2.0 is the lack of the EIM (equipment interface module) and the redlink gateway. I have found the WiFi thermostat to be less feature rich, and it doesn't provide all the optional sensors (duct, outdoor or humidification) that the extra cost and installation time of the Prestige system provides. However, setup is simpler, wiring is simple, and I have found the wifi connection to be more reliable in terms of connectivity. I have one Prestige 2.0 in use that constantly complains about connection failure due to thick walls and concrete interfering with the signal. You can always add a wifi repeater on another level if you experience wifi issues, but here is no great work around that I am aware of for the Prestige in this scenario.
Price wise, the VisionPro 9000 is cheaper than the Nest, currently selling on Amazon for $205.99. This strategically places it below the competitors and its bigger brother the Prestige 2.0. It lacks the auto-awareness sensors of the Nest thermostat, but as long as you can live with that, the capabilities of Honeywell wifi thermostat, as well as the email notification features make up for that deficit.
Amazon Honeywell wifi reviews