There is no all-round compounder. No individual extruder can handle equally well all the challenges posed in practice. Key for specific compounding tasks are often the individual steps, such as feeding of poorly flowing or very high-volume additives, efficient melt degassing, or particularly gentle plasticization of sensitive plastic compounds. So which extruder is best for the task in hand? Alternatively, which extruder can flexibly handle the widest range of compounding applications cost-effectively? Moreover, when is a customized solution the best? A brief introduction in evaluation methodologies are given and illustrated with practical examples.