Roasting should bring out the subtle nuances of flavor that each coffee variety contains. Each coffee has a number of characteristics which emerge at different roast levels, from light to dark.
For many coffees, the best flavor is found at a bit lighter roast level. However, defects will also often show up at those optimum roast levels, so starting out with good green coffee is essential. Over-roasting will mask those defects. (Of course, with the right marketing campaign a whole life-style can be packaged and sold in the process. Charred coffee is available for big bucks on almost any street corner.)
Perhaps it’s a personal weakness, but the Red Finn likes to tinker with coffees; finding nuances which compliment one another, brewing up synergistic blends which deliver satisfying complexity. Roasting is done in small batches, ensuring the freshest product possible.