From what I gather the air flow control/heat control is excellent - affords a lot of temperature stability and allows it to range from pizza oven (super hot) to smoker.Charcoal (which gives you a good variety of flavour profiles) plus heats up fast and stays hot. Can also be used as a smoker. Well designed and smart attachments. Kind of like how the old Macs were once a cult alternative to Windows based machines.
Also built like a tank.
One knock I've seen is about flaking paint. Not sure if it's a common concern (or terribly important).