Hard drives can churn fast enough now-a-days that unless your perl program is over a meg, I doubt you'll notice much during loading.

I never want my packages autoupdated unless it's a standalone product that's understood to be updated as such. For instance, if there's a bug in the package and i code around the bug, once the package fixes said bug, it may break my code. I may rather the old version due to unreconcilable issues with the newer one.

Change management is not something that's easy to automate. All we can do is create tools to make it easier.