Module-based projects: when to use them or not use them

[MindX]

I'm starting to familiarize myself with using the module-based architecture for zend framework projects. My real reason behind being interested in the module architecture is to be able to take a module from one project and just drop it into another project. Maybe I'm not getting it right..But what I'm noticing right off the bat is that controllers within each module cannot have the same name as any other controller in the main application (or in any other module, though I haven't tested this). This leads me to think that modules are not really independent self-contained units, so I wonder how this affects their ease of distribution from one project to another.The other issue is what if I were to take a module and drop it into another project. Do I have to update the \[code\].zfproject.xml\[/code\] manually? and wouldn't that be a bit too cumbersome to be done manually? Maybe I'm not clear on how modules should be used in zend, so I'd like to know when you decide it's best to use them, and when do you decide not to use them, or do you use them all the time, or do you never use them?