A roaster must both deliver heat and move coffee beans so that the batch develops as intended. A rotating drum and an air-driven system approach those tasks differently. The machine design is therefore more than an exterior shape or a simple claim about maximum temperature.
In a drum roaster, beans move inside a rotating chamber and receive heat through a combination of contact and the surrounding hot environment. An air roaster uses airflow to transfer heat and agitate the beans. A fluid-bed design suspends or moves coffee in a sufficiently strong air stream.
Batch machines roast a defined charge and then begin again; continuous equipment is built around a different production flow. For an equipment comparison, establish realistic batch size, ventilation requirements, energy supply and operator access before comparing control screens. Temperature figures also need context: different probes can measure different parts of the system. A machine specification alone does not establish the flavor of its coffee or remove the need for careful operation and repeatable records.
The conversation
A good question can make a better brew.