Haven't bought one... not a requirement.
Am not trying to bust your bubble... the first task on the learning curve is to master a fire management technique without
a secondary electronic device. A consistent fire technique should be the foundation of every cook you will encounter.
Here's why... that device (and you) will be dependent on a power source. What will happen if the device malfunctions, lose power and fail for any reason?
What will be your plan B?
Believe it or not... there are competitions (see the Go Naked event in Chambersburg, PA) which prohibits such devices.
Strictly only charcoal/wood fire and air vents only... no propane, pellets, or controllers - completely relying on a Pitmaster's skill.