Use of arrays considered harmful?
The big cost in IT is usually in development and maintenance, not in deployment costs. Most projects are small, not Amazon size deployments so I believe that unless you are sure that you are building a very large scale system, it is best to optimize development to reduce costs for small and medium size systems. Smaller code size means smaller costs. Java programs should be as short and concise as possible and generics and use of collections helps a lot. Sometimes when I read the source for Java programs it looks like the authors were paid by line of code :-)