Web Part Deployment Best Practices?

In articles on MSDN that talk about creating basic web parts, they talk about deployment by importing a .DWT. However, there is also an article on “Using Wppackager to Package and Deploy Web Parts for Microsoft SharePoint Products and Technologies” along with the Wppackager download. This, plus a post I ran across that complained about web part deployment, got me wondering... Are there best practices for web part deployment? What are they? Are there scenarios where distributing a simple .dwt makes sense, and others where you really should be using wppackager? I'd love to hear your thoughts and comments on the topic, and I'm guessing a few other folks would, as well!