This entry in the documentation covers this topic a bit:
Recently, I was considering the implications of upgrading a project as well. In my case I decided that upgrading the CLI wouldn’t be worth it.
Don’t get me wrong. I love the CLI and use it exclusively when creating a new project, but I don’t feel it offers a compelling reason to upgrade for the sake of using the latest. It’s great to get up and running quickly. However, I’m sure I’m not using it to its full potential. But I will definitely use the latest for any new projects.
On the point of bundlers/loaders, I switched an existing project from RequireJS to Webpack once Webpack was available via the CLI. I found the easiest way to make the switch was to simply run the CLI and have it build out the Webpack version, then move my existing project into it and fix the issues.
I chose Webpack because I’m generally a “use what’s battle tested and widely adopted” sort of person. I’m not keen on jumping into new or obscure tech with little documentation or community support. With that in mind, I will say that Webpack isn’t something that’s intuitive… at all. I honestly barely know a thing about it. Fortunately, the CLI set things up so I don’t really have to know much if I don’t want to.
I’m interested in writing code to get stuff done, not muck about in configuration nonsense. Which is exactly why I love Aurelia.