roaster type
Qban;
An interesting topic that can stir many long-winded and highly opinionated discussions beween participants holding diverse opinions - especially at a venue such as the roasters guild. I once heard a roaster state that "drum roasters suck", while another responded cheerily that "fluid bed roasters blow".
I have done extensive comparative cupping and have roasted coffee with several different machines of different brands and styles. While I have some well-formed opinions and preferences of my own, the only useful disclaimer to the following statements is to: avoid seriously flawed equipment.
Nearly any roaster can roast coffee. Many can roast coffee quite well. FRESHNESS, QUALITY OF RAW MATERIALS (green), & THE SKILL OF THE OPERATOR mean much more in the equation than the particulars of the equipment.
Furthermore, a coffee can not become better then the intrinsic character of the green. A skilled roaster can reveal more of the cup characteristics and can tailor the roast for different brewing styles. However a poorly skilled roaster can easily dull the coffee during roasting or blend and roast a coffee poorly suited to the brewing style (particularly when brewing espresso). Similarly the coffee can yield a cup far below the potential intrinsic character - if the coffee is poorly blended, poorly roasted, poorly packaged, poorly stored, not fresh, not ground/brewed fresh, brewed poorly, or served poorly.
Concern yourself less with the specific details of your roaster's equipment and more with their cup quality, commitment to freshness, and commitment to service.