At least in the Enterprise world, the maintenance phase significantly outlasts the design and implementation phase in the majority of projects so any gains in t

At least in the Enterprise world, the maintenance phase significantly outlasts the design and implementation phase in the majority of projects so any gains in those phases are usually dwarfed by the latter phases. The system I'm currently migrating has been in production for 10 years. The original developers are long gone, as are the generation after that. It's code archeology at its finest. As you say its a trade off, but IMHO its always better to pick maintainability over efficiencies in design and implementation for most long term projects. (Not you say can't write maintainable Perl, its just much more difficult than in other languages and requires a solid culture to support it).